Abstract: FDM (Fused Deposition Modelling) is the most popular 3D printing technology worldwide due to its simplicity and low costs. One of the key points of FDM is the need for supporting material to realize the overhanging features. In general, however, both in the case of printing supports with the same material as the part and in the case of printing with soluble supports, there is a high waste of material and a significant increase in the printing time to get the finished part. One of the fundamental parameters for generating supports within the slicer software is the so-called “support overhang angle”, which consists of the maximum achievable angle beyond which the slicer generates supports. The other key parameter in FDM printing is the “layer height”, which directly determines both the quality of the final part, its strength, and the printing time itself. This paper will therefore attempt to investigate the relationship present between “layer height” and “support overhang angle”, bringing some examples of how with proper layer height one can significantly reduce support generation, wasted material and in some cases also printing time.

Keywords: FDM | Layer Height | Overhangs

Abstract: Additive Manufacturing is widely applied in aerospace, automotive and marine engineering. Indeed, large-scale components are often required in these applications, such as for non-structural parts of aircraft, spare parts or small lots of cars or marine components. Fused Deposition Modelling is one of the Additive Manufacturing processes used to affordably convert digital models into mockups, prototypes, and functional parts: a slicing software converts the object’s digital model into a list of instructions for the machine. However, commercial slicing software packages often fail to accurately estimate the time required to produce models, especially when their size is significant: the errors could be up to several hours, which cannot be adequate in a real-life industrial context where production must be scheduled in a precise way. This manuscript compares the build time estimation of several commercial slicing software considering a real-life part. Furthermore, the evaluation of the manufacturing setting mainly affects the error in estimating the build time achieved through a Design of Experiment approach. The more time-impacting printing parameters have been detected, allowing fine helpful tuning to increase the accuracy of the build time in commercial slicing software. A case study included in the manuscript supports the analyses. Proper setting of the commercial slicing software can significantly improve the accuracy of the printing time.

Keywords: Additive Manufacturing | Design of Experiment | Fused Deposition Modelling | Slicing | Time Estimation

Abstract: The paper focuses on the application of 3D printing technology in the medical field, particularly in cardiac surgery. Unlike traditional imaging techniques such as CT, MRI, and ultrasound, 3D printing offers a more detailed understanding and analysis of clinical cases. By using 3D printing, it becomes possible to study a patient’s specific cardiac anatomy, manipulate objects before surgery, and accurately determine the surgical site. This reduces both the time required for the operation and the patient’s recovery period. This study presents a methodology for creating 3D-printed models of aortic arch sections affected by aortic dissection. The aim is to produce anatomical models with varying levels of quality and accuracy. The research goal is to assess the differences in 3D printing materials and technologies for creating complex anatomical models like the aorta. The process involves segmenting medical images obtained from Computed Tomographic Angiography (CTA) and then 3D printing digital models using different materials (such as PLA, TPU, and resin) and technologies (like FDM and SLA). The resulting 3D printed models are low-cost and demonstrate good accuracy in reproducing human anatomy.

Keywords: 3D Printing | CAD | Cardiac surgery | Engineering method

Abstract: Additive Manufacturing (AM) is continuously increasing its appeal as a breakthrough production process due to well-established advantages compared to traditional manufacturing strategies based on chip removal or casting. The design of lightweight structures can exploit the AM advantages, thanks to the capability of shaping complex geometries where the constant level of stress can be achieved through Topology Optimization. Moreover, in transportation engineering and lightweight structures in general, thin-shell or thin-walled components are widely used for frames, fuselages, wings, car bodies, coaches, tanks or recipients. However, the application of topology optimization routines on thin-walled structures is not exempt from difficulties. This is true especially in the case of a distributed pressure load coming from fluid-structure interaction analysis. Coupling the benefits of TO methodology with the already good performances of thin-walled structures may lead to mechanically efficient shapes. This research addresses strategies to apply topology optimization on thin-walled structures. The effect of the local concentration of distributed load in a cloud of control points distributed along the surface of interest is considered and tested. Two case studies coming from industrial engineering have been carried out to show the capabilities of the proposed approach.

Keywords: Additive Manufacturing | Design for Additive Manufacturing | Distributed load | Thin-walled structure | Topology Optimization

Abstract: ‘Repair’ in the design process of products can prolong the life cycle of parts: this is substantiated by a few examples that put this ideology into practice. Among many other products, home printers could be a good example, with huge numbers of printers ending up in landfill after a relatively short life; often due to blocked print heads that are either impossible or too expensive to replace. The act of fixing things can both prolong the life of an artifact, and create new values through the process of engagement for its users. However, the prohibitive cost of repair makes it inaccessible or unfavorable this practice for many. In this paper a preliminary approach to Design for Repair is proposed, in order to virtually test an industrial case study and to show a comparison between a product, that was intended to disposal after a failure of some components, and the same product re-designed, by taking into account how to repair parts in easy and effective way. Redesign of parts in some cases can be very effective and the virtual test can be easily reproposed in practice, for industrial products. Advantages in the repair of parts is evident in terms of sustainability and circular economy pursuit. This paper suggests a sequenced method to approach the Design for Repair and provide the virtual model of a re-designed solution that could replace the previous one in order to make the repair of components easy and effective. The economic analysis on the effective convenience of repair faced to the disposal of a product was not developed within this context.

Keywords: Circular economy | Design for Disassembly | Design for Repair | Gearmotor | Sustainability

Abstract: Purpose: The aim of this research is to enlighten the methodology model of Industrial Design Structure (IDeS) that integrates the internal and external customer feedback embodied both in methods of quality function deployment (QFD) and as basis of design for six sigma (DFSS) steps to systematically bring the information across the entire organization, saving overall product development time and resources. Design/methodology/approach: The paper describes the state of the art enlightened to establish the disadvantages and challenges of other methods taken into consideration in the study like QFD and DFSS that, together with the need of companies to react fast to changes they need to straightforwardly implement product development information across all departments, leading to a mass customization infrastructure. Several application trials of this methodology have been cited. Findings: The IDeS method has established to been able to integrate other well-known methodologies to gather technical specifications starting from voice of customers (VOCs) like QFD that served to canalize the generalist approach of define, measure, analyze, design and verify (DMADV) of DFSS in order to reach into a larger share of the organization and englobe by following the overall product design steps of an industrial project. Research limitations/implications: The research approach chosen for this document presents the concept of a methodology ought to operate most internal branches in a company driven by product design requirements and guidelines. Therefore, researchers are encouraged to develop further studies on the IDeS method are required in order to adapt this methodology to specific management tools that would help to ease information gathering for immediate analysis and modification. Practical implications: The paper implicates that a need to interchange information systematically across all subdivisions in the organization, as brisk response to VOC reactions is needed to thrive in the market nowadays, leading to a fast product customization scene. However, the industry is heading into adopting an individual customer-centered product conceptualization ought to be driven by design as a key for individualizing an object. Afterward by taking this concept broadly and adopting it would lead to implement a company organization that would be directly affected by the customer's input. Social implications: The methodology described aims to enable organizations to portray fast and accurate product prototyping, by exploiting technologies from Industry 4.0. Originality/value: This concept proposes a method to canalize the implementation of DFSS by using the DMADV approach, whilst assessing the challenges of adaptation and keeping up with cultural pace that impacts the behavior of buying and consumption and moreover implementing a seamless communication within all departments in the organization to share the development progress and change requests by using similar information technology tools. This would imply important savings in resources, whilst delivering quality products to the society.

Keywords: DFSS | Engineering | IDeS | Industrial design | QFD | Quality | Six sigma

Abstract: The following scientific paper aims to analyze in detail the methodology for reverse engineering of a racing motorcycle connecting rod. The objective is to start with a product available on the market as a spare part, reconstruct its CAD model with a high standard of accuracy, then proceed with lightening modifications to arrive at a new, improved design. The innovative aspect of the procedure lies in the fact that in order to ensure accuracy on the order of a tenth of a millimeter during reconstruction, it was decided to use a FARO articulated arm laser to scan the component’s outer surface. By taking advantage of appropriate redesign CAD software (Geomagic Design X), a reconstruction can proceed within the high standard of accuracy imposed. In conclusion, the modifications made through material removal allow an improvement in product efficiency, ensuring high performance.

Keywords: CAD modelling | conrod | high-precision modeling | redesign | reverse engineering

Abstract: Industrial engineering applications often require manufacturing large components in composite materials to obtain light structures; however, moulds are expensive, especially when manufacturing a limited batch of parts. On the one hand, when traditional approaches are carried out, moulds are milled from large slabs or laminated with composite materials on a model of the part to produce. In this case, the realisation of a mould leads to adding time-consuming operations to the manufacturing process. On the other hand, if a fully additively manufactured approach is chosen, the manufacturing time increases exponentially and does not match the market’s requirements. This research proposes a methodology to improve the production efficiency of large moulds using a hybrid technology by combining additive manufacturing and milling tools. A block of soft material such as foam is milled, and then the printing head of an additive manufacturing machine deposits several layers of plastic material or modelling clay using conformal three-dimensional paths. Finally, the mill can polish the surface, thus obtaining a mould of large dimensions quickly, with reduced cost and without needing trained personnel and handcraft polishing. A software tool has been developed to modify the G-code read by an additive manufacturing machine to obtain material deposition over the soft mould. The authors forced conventional machining instructions to match those of an AM machine. Thus, additive deposition of new material uses 3D conformal trajectories typical of CNC machines. Consequently, communication between two very different instruments using the same language is possible. At first, the code was tested on a modified Fused Filament Fabrication machine whose firmware has been adapted to manage a milling tool and a printing head. Then, the software was tested on a large machine suitable for producing moulds for the large parts typical of marine and aerospace engineering. The research demonstrates that AM technologies can integrate conventional machinery to support the composite materials industry when large parts are required.

Keywords: additive manufacturing | aerospace engineering | Fused Filament Fabrication | G-code | hybrid manufacturing | marine engineering | mould

Abstract: (1) Background: The application of computer-aided planning in the surgical treatment of post-traumatic forearm deformities has been increasingly widening the range of techniques over the last two decades. We present the “flipping-wedge osteotomy”, a promising geometrical approach to correct uniapical deformities defined during our experience with virtual surgical planning (VSP); (2) Methods: a case of post-traumatic distal radius deformity (magnitude 43°) treated with a flipping-wedge osteotomy in an 11-year-old girl is reported, presenting the planning rationale, its geometrical demonstration, and the outcome of the procedure; (3) Results: surgery achieved correction of both the angular and rotational deformities with a neutral ulnar variance; (4) Conclusions: flipping-wedge osteotomy may be a viable option to achieve correction in forearm deformities, and it deserves further clinical investigation.

Keywords: computer-aided surgery | forearm deformity | malunion | osteotomy | pediatric | post-traumatic | VSP

Abstract: Design for Disassembly (DfD) and Augmented Reality (AR) have become promising approaches to improve sustainability, by providing efficient delivery and learning assets. This study combines DfD and AR to deliver a method that helps to streamline maintenance processes and operator training. It focuses on a common part in the process industry that requires frequent maintenance and repair. DfD was applied to the pump’s design to ease disassembly and reduce material waste, energy consumption, and maintenance time. AR was used to provide an interactive guide to improve the operator understanding of its internal parts and assembly/disassembly procedures. The resulting DfD-AR led to a reduction in maintenance time and shows potential to deliver better training. This highlights the potential of DfD and AR to enhance sustainability, learning, and productivity. The resulting disassembly sequence was taken to an AR simulation, helping process designers to better understand the procedure and further optimize the solution with other constraints.

Keywords: Augmented reality (AR) | design for disassembly (DfD) | optimization | recycling

Abstract: In wide-ranging areas, including hydraulics, biomedical, automotive, and aerospace, there is often a need to move a fluid with a constant flow rate. This is difficult to achieve with any type of pump and usually other elements are inserted to regularize the output. This study focused on the peristaltic pump because there are few studies on it and it has some interesting features, such as extreme simplicity, a small number of components, and the extreme compactness of the whole system. The first part of this study is focused on analyzing the classical geometry of the peristaltic pump to understand the origin of the discontinuity in the flow rate; the second part proposes a new geometry that mitigates the flow irregularity by more than 200%. In this way, it is possible to use it in all the sectors where a constant flow rate is required but where insulation between the fluid and the machine is required. Together with the flow study, an analysis of how the main geometric parameters affect the operation of the pump is provided, complete with explanatory graphs and tables. A prototype made through additive manufacturing technologies is also proposed.

Keywords: 3D printing | calculation | constant flow rate | fluid transfer | peristaltic pump

Abstract: (1) Background: The adoption of Virtual Surgical Planning (VSP) and 3D technologies is rapidly growing within the field of orthopedic surgery, opening the door to highly innovative and individually tailored surgical techniques. We present an innovative correction approach successfully used in a child affected by “windswept deformity” of the knees. (2) Methods: We report a case involving a child diagnosed with “windswept deformity” of the knees. This condition was successfully addressed through a one-stage bilateral osteotomy of the distal femur. Notably, the wedge removed from the valgus side was flipped and employed on the varus side to achieve the correction of both knees simultaneously. The surgical technique was entirely conceptualized, simulated, and planned in a virtual environment. Customized cutting guides and bony models were produced at an in-hospital 3D printing point of care and used during the operation. (3) Results: The surgery was carried out according to the VSP, resulting in favorable outcomes. We achieved good corrections of the angular deformity with an absolute difference from the planned correction of 2° on the right side and 1° on the left side. Moreover, this precision not only improved surgical outcomes but also reduced the procedure’s duration and overall cost, highlighting the efficiency of our approach. (4) Conclusions: The integration of VSP and 3D printing into the surgical treatment of rare limb anomalies not only deepens our understanding of these deformities but also opens the door to the development of innovative, personalized, and adaptable approaches for addressing these unique conditions.

Keywords: 3D printing | autograft | cutting guide | in-hospital | patient-specific instruments | pediatric | point-of-care | VSP | windswept deformity

Abstract: This study aims to evaluate the advantages and criticalities of applying additive manufacturing to produce climbing holds replicating real rocky surfaces. A sample of a rocky surface has been reproduced with a budget-friendly 3D scanner exploiting structured light and made in additive manufacturing. The methodology is designed to build a high-fidelity replica of the rocky surface using only minor geometry modifications to convert a 2D triangulated surface into a 3D watertight model optimised for additive manufacturing. In addition, the research uses a novel design and uncertainty estimation approach. The proposed methodology proved capable of replicating a rocky sample with sub-millimetre accuracy, which is more realistic than conventional screw-on plastic holds currently used in climbing gyms. The advantages can be addressed in terms of customisation, manufacturing cost and time reduction that could lead to real outdoor climbing experiences in indoor environments by coupling additive manufacturing techniques and reverse engineering (RE). However, operating the scanner in a rocky environment and the considerable size of the climbing routes suggest that further research is needed to extend the proposed methodology to real case studies. Further analysis should focus on selecting the best material and additive manufacturing technology to produce structural components for climbing environments.

Keywords: 3D scanning | Additive manufacturing | Climbing holds | Fused deposition modelling | Reverse engineering | Uncertainty quantification

Abstract: The present study was set to validate two different suburban-type sportscar bodies with shared common underpinnings. The chosen method to develop this project was the Industrial Design Structure (IDeS), which characterizes the ability to use the different innovative techniques known within the industrial field, across the whole organization. This method is embodied by following a series of structured analysis tools, such as QFD (Quality Function Deployment), Benchmarking (BM), Top-Flop analysis (TFA), Stylistic Design Engineering (SDE), Prototyping, Testing, Budgeting and Planning. This project aims to study the present-day car market and to foresee deployment in the near future. This attempt was confirmed by delivering the complete styling and technical feasibility characteristics of two different sports cars, obtained by the IDeS methodology. This approach of embodying design together with phases of product development would provide a better engineered, target-oriented product, that uses state-of-the-art style and CAD environments to reduce product development time and, hence, overall Time to Market (TTM).

Keywords: benchmarking (BM) | industrial design structure (IDeS) | quality function deployment (QFD) | sportscar | stylistic design engineering (SDE) | suburban mobility | Top-Flop analysis (TFA)

Abstract: The lifecycle of a product is getting shorter in today’s market realities. Latest developments in the industry are heading towards achieving products that are easy to recycle, by developing further technological advances in raw materials ought to include input from End of Life (EOL) products so a reduction of natural harm could be achieved, hence reducing the overall production environmental footprint. Therefore, the approach taken as a design for environment, a key request nowadays in order to develop products that would ease the reverse manufacturing process leading to a more efficient element recycling for later use as spare parts or remanufacturing. The methodology proposed compares three probable disassembly sequences following a comparison of literature-found procedures between genetic algorithms and as a “state space search” problem, followed by a hybrid approach developed by the authors. Time and evaluation of these procedures reached to the best performing sequence. A subsequent augmented reality disassembly simulation was performed with the top-scored operation sequence with which the user is better able to familiarize himself with the assembly than a traditional paper manual, therefore enlightening the feasibility of the top performing sequence in the real world.

Keywords: closed loop | Disassembly | genetic algorithms | metaheuristic method | optimization | particle swarm optimizer

Abstract: Well-established advantages as design freedom, acceleration of design-to-manufacturing cycle, decreased internal logistics reflect on the wider application of Additive Manufacturing as the main manufacturing process. However, its application to large-scale components manufacturing is still an open challenge, because of the limited printing volume available in off-the-shelf machines, slow manufacturing process, and low production volume. After a review of the available contributions, this paper proposes a methodology to handle large-scale 3D models, to be applied before the slicing process. The methodology is based upon the large-scale component subdivision into subparts within CAD environments, using an innovative approach tailored to the problem, and exploits the multi-head capability of collaborative large-scale AM machines. A UAV fixed-wing shows the positive effects in terms of speeding up the manufacturing process. The approach can significantly reduce the printing time of large parts, but a new generation of Additive Manufacturing machines is required to exploit the methodology.

Keywords: Additive Manufacturing | Aerospace | Automotive | Collaborative Manufacturing | Large-Scale Part | Multi-head Extruder

Abstract: The panel method is a potential-flow numerical approach that shows valuable performances to solve aerodynamic problems in the preliminary design stages. It shows a lower computational effort compared with Computational Fluid Dynamics, wind tunnel tests or ‘on the field’ experiments. However, the 3D surface discretization in rectangular panels is tedious and must be often carried out manually from scratch. Moreover, the panel method can’t be used to compute the overall drag force due to strong assumptions. To solve these two challenging aspects, the authors propose a voxel-based fluid dynamic approach integrating its programmed functions within a panel method. Voxelization is used to automatically distribute coherently the panels along the external surface of a 3D model in an automated way. A parametric study is included to demonstrate how the voxel resolution affects the aerodynamic results and provide guidelines for future research. Overall drag is estimated using corrections for both the skin friction and the form drag sources. The Ahmed body case study is included and demonstrates a good agreement between the voxel-based fluid dynamics approach and the literature benchmarking values, but with lower computational efforts. Further studies involving more complex shapes should be performed to better understand the performances and limitations of the approach.

Keywords: Ahmed body | Automotive | CAD | Conceptual Design | Panel method | Voxelization

Abstract: Many industrial technologies are developed to optimize products and bring innovation. In particular, the automotive sector is renewing itself according to the rules of green energy and consumption. This huge change requires a reinterpretation of the models on the market updating them to the present and the future needs of automotive industry. In this paper the best compromise between innovation and tradition is found for the Ford brand that has not yet presented electric cars in the sedan segment. Following the SDE method enriched with Quality Function Deployment (QFD), Benchmarking (BM) and Top Flop Analysis (TPA), it is possible to carry out an innovative project. All these technologies must, however, be ordered according to a specific product allowing the best result for the design process. It is therefore necessary identifying the most common stylistic trends in order to draw the external styling of the vehicle using virtual prototyping techniques. To achieve an innovative result, Augmented Reality (AR) is considered to complete the method substituting the static and expensive procedure of making maquettes.

Keywords: Additive manufacturing | Augmented reality | Benchmarking | Car design | Design engineering | QFD | Stylistic design engineering (SDE)

Abstract: The Panel method is an approach for the estimation of the lift of 3D models which is faster than CFD. This can be useful especially in the conceptual design stage where several configurations should be evaluated in a reduced time with a limited computational cost. However, the meshing of the 3D body surface with rectangular panels can be a time-consuming activity because the designer should define from scratch a cloud of points that matches the external surfaces of the tested object to obtain consistent panelling. Therefore, a voxelization-based methodology has been developed to obtain the panels’ position, speeding up and automating the model preparation process. The obtained discretization has been integrated into a panel method available in the literature. Four case studies, of increasing complexity, have been analyzed to investigate the capability of the innovative voxel-based panel methodology. A parametric study has been carried out to study the effect of the voxel grid dimension on the accuracy of the results. Benchmarking values of lift coefficient obtained from literature or xFoil software have been used to evaluate the precision that can be achieved with this approach. The results show a good agreement between the voxel-based panel method and the literature when the overall pressure distributions and aerodynamic coefficient values are considered. Higher errors are noticed with drag.

Keywords: Fluid dynamics | Panel method | Potential flow | Voxelization

Abstract: Torsional deformities of the lower limb are common in children with cerebral palsy (CP)-determining gait problems. The mechanisms underlying transverse plane gait deviations arise from a combination of dynamic and static factors. The dynamic elements may be due to spasticity, contractures and muscle imbalances, while the static ones may result from excessive femoral anteversion, which decreases the efficiency of the hip abductors by reducing the muscular lever arms. A therapeutic approach has been identified in multi-level functional surgery for the lower limb. Treating the malalignments of the lower limb with femoral or tibial derotation provides optimal results, especially when supported by adequate biomechanical planning. This planning requires an integrated static-dynamic approach of morphological and functional evaluation, based on radiological measurements, physical examination and gait analysis. Instrumented gait analysis has been confirmed as essential in the evaluation and surgical decision making process for children affected by CP with transverse plane deformities. Computational simulations based on musculoskeletal models that integrate patient-specific CT morphological data into gait analysis can be used for the implementation of a surgical simulation system in pre-operative planning to test the possible effects of the different surgical treatment options on the torsional defects of the lower limbs. Recently, a computer-aided simulation process has been implemented in the preoperative planning of complex osteotomies for limb deformities in children. Three-dimensional (3D) digital models were generated from Computed Tomography (CT) scans, using free open-source software. The aim of this study is to integrate the patient-specific CT musculoskeletal model with morphological data and gait analysis data, with the personalized calculation of kinematic and kinetic parameters, which allow us to generate an “avatar” of the patient for a more in-depth evaluation of the gait abnormalities. The computational simulation platform proposed provides a realistic movable musculoskeletal model in a virtual environment, with the possibility of planning and monitoring the effects of virtual three-dimensional surgical corrections.

Keywords: avatar | cerebral palsy | computed tomography | derotation | gait analysis | musculoskeletal modeling | torsional deformities | virtual surgical planning

Abstract: In the last decades, the flourishing of Additive Manufacturing (AM) promoted innovative design solutions in many different sectors. Despite the numerous advantages of AM technology, there are still open challenges in the field. In Fused Deposition Modelling (FDM) structures the layer-by-layer manufacturing process induces anisotropy in the material properties of the structures. The correct characterization of the mechanical properties is fundamental in the design and development stages but at the same time difficult to achieve. The experimental approach can be extremely long and expensive. An alternative is the use of an accurate numerical approach and performing a Finite Element Analysis (FEA) of the geometry which is effectively printed. However, to the best of the authors' knowledge, there is not a common and well-established procedure to reconstruct the real geometry which is generated after the slicing process. In this paper, starting from the information provided by the G-CODE, an easy-to-use, and reproducible methodology to reconstruct the printed geometry is presented. The performance of the innovative approach is evaluated via qualitative observations by referring to several case studies. The results are thoroughly analysed, and future trends and research needs are highlighted.

Keywords: Additive Manufacturing | CAD | Fused Deposition Modelling | G-CODE

Abstract: Fused Deposition Modelling (FDM) technology allows to choose a large variety of materials and it is widely used by companies and individuals nowadays. The cost effectiveness of rapid prototyping is achievable via FDM, that makes this technology useful for research and innovation. The application of 3D printing to aid production is the most common approach. Moreover, the use of 3D printing in prototypes result in a waste of material since no reuse is considered. In the following manuscript, this technology is applied to mould fabrication by achieving a low surface roughness at a modest cost compared to conventional manufacturing methods. Moreover, the possibility to use a combination of thermoplastic materials is analysed by examination of the CAD model optimized for Additive Manufacturing (AM) from scratch and was verified using metrology tools. Several moulds were finally built and applied to the specific case study of carbon fibre laminated components. This manuscript aims to analyse the manufacturing process by comparing the mould surface geometry before and after the smoothing process. The achieved tolerance between the produced moulds is ±0.05 mm that ensures the repeatability of the process from an industrial point of view; whilst the deviation between CAD and mould is ±0.2 mm. To combine an accurate FDM process together with chemical smoothing proved to be a powerful strategy to produce high quality components that can be inserted in the production process by means of traditional manufacturing techniques. This will aid to reduce the cost of standard manufacturing for low production batches and prototypes of carbon fibre composites.

Keywords: Carbon fibre mould | Chemical smoothing | FDM | Multimaterial FDM | PLA | PVB | Vapor smoothing

Abstract: Lightweight bioinspired structures are extremely interesting in industrial applications for their known advantages, especially when Additive Manufacturing technologies are used. Lattices are composed of axial elements called ligaments: Several unit cells are repeated in three directions to form bodies. However, their inherent structure complexity leads to several problems when lattices need to be designed or numerically simulated. The computational power needed to capture the overall component is extremely high. For this reason, some alternative methodologies called homogenization methods were developed in the literature. However, following these approaches, the designers do not have a local visual overview of the lattice behavior, especially at the ligament level. For this reason, an alternative mono-dimensional (1D) modeling approach, called lattice-to-1D is proposed in this work. This method approximates the ligament element with its beam axis, uses the real material characteristics, and gives the cross-sectional information directly to the solver. Several linear elastic simulations, involving both stretching and bending dominated unit cells, are performed to compare this approach with other alternatives in the literature. The results show a comparable agreement of the 1D simulations compared with homogenization methods for real tridimensional (3D) objects, with a dramatic decrease of computational power needed for a 3D analysis of the whole body.

Keywords: homogenization | lattice structure | periodic structure | structural analysis | voxel

Abstract: A deep research and analysis of a “critical waste” object has been carried out, understood as a subject that does not fare high on the separate collection and recycling system yet: the cigarette butt. This acknowledged social waste is the first among all the garbage detected everywhere around neighborhoods worldwide, and is therefore the epicenter of a situation so worrying that it is necessary to find a solution concerning the environmental pollution. The present exercise was developed, by means of proper product design methods like TRIZ and QFD driven by DFSS rulings, to conceive of new products and services in order to create incentive for the smokers to lessen the environmental pollution problem. The social implications are about the possibility of modifying the bad habits of the smokers and making the user act consciously towards the environment. Throwing the cigarette-stub in the new collection device, rather than on the ground, enables users to enjoy both moral and economic returns. The “Buttalo” service is aimed to incentivize the population to fight against environmental pollution whilst helping smokers to be conscious about it.

Keywords: benchmarking analysis | Design for Six Sigma (DFSS) | quality function deployment (QFD) | Top-Flop analysis | TRIZ

Abstract: Complex deformities of lower limbs are frequent in children with genetic or metabolic skeletal disorders. Early correction is frequently required, but it is technically difficult and burdened by complications and recurrence. Herein, we described the case of a 7-year-old girl affected by severe bilateral genu varum due to spondyloepiphyseal dysplasia. The patient was treated by patient-specific osteotomies and customized structural wedge allograft using Virtual Surgical Planning (VSP) and 3D-printed patient-specific instrumentation (PSI). The entire process was performed through an in-hospital 3D-printing Point-of-Care (POC). VSP and 3D-printing applied to pediatric orthopedic surgery may allow personalization of corrective osteotomies and customization of structural allografts by using low-cost in-hospital POC. However, optimal and definitive alignment is rarely achieved in such severe deformities in growing skeleton through a single operation.

Keywords: 3D-printing | cutting guide | in-hospital | osteotomy | patient-specific instruments | pediatric | point-of-care | spondyloepiphyseal dysplasia | structural allograft | VSP

Abstract: Improvements in software for image analysis have enabled advances in both medical and engineering industries, including the use of medical analysis tools to recreate internal parts of the human body accurately. A research analysis found that FDM-sourced elements have shown viability for a customized and reliable approach in the orthopedics field. Three-dimensional printing has allowed enhanced accuracy of preoperative planning, leading to reduced surgery times, fewer unnecessary tissue perforations, and fewer healing complications. Furthermore, using custom tools chosen for each procedure has shown the best results. Bone correction-related surgeries require customized cutting guides for a greater outcome. This study aims to assess the biopolymer-based tools for surgical operations and their ability to sustain a regular heat-sterilization cycle without compromising the geometry and fit characteristics for a proper procedure. To achieve this, a DICOM and FDM methodology is proposed for fast prototyping of the cutting guide by means of 3D engineering. A sterilization test was performed on HTPLA, PLA, and nylon polymers. As a result, the unique characteristics within the regular autoclave sterilization process allowed regular supplied PLA to show there were no significant deformations, whilst annealed HTPLA proved this material’s capability of sustaining repeated heat cycles due to its crystallization properties. Both of these proved that the sterilization procedures do not compromise the reliability of the part, nor the safety of the procedure. Therefore, prototypes made with a similar process as this proposal could be safely used in actual surgery practices, while nylon performed poorly because of its hygroscopic properties.

Keywords: 3D engineering | Cutting guide | FDM | HTPLA | Nylon FDM | Preoperative planning | Sterilization

Abstract: The evolution of innovative and systematic design methodologies over time has widened the design concept involvement from the product development phase, which also includes the production and start-up phases. Literature findings have presented to accomplish a Generative Design (GD) approach through the application of an innovative method called Industrial Structure Design (IDeS), a systematic design method able to discover the customer’s needs and the fundamental technical solutions to obtain a good innovative product, involving the whole organization for this achievement. Nevertheless, there is a social demand for solutions to the dramatic and growing problem of marine pollution from plastic materials, encouraging the designers to conceive a new innovative drone for waste collection at sea. Therefore, this study aims to merge all the most advanced design technologies with IDeS in an integrated way, by generating a structure that can also be adopted to plan the organization of a production company. The approach is validated with the design of the Recovery Plastic Drone (RPD) obtained with the IDeS methodology, combining Design and Product development phases, leading to a better and innovative solution for the market.

Keywords: Design Sea | Generative Design (GD) | Industrial design structure (IDeS) | Plastics Recovery Drone (PRD) | Quality function deployment (QFD) | Stylistic design engineering (SDE)

Abstract: The topology optimization methodology is widely applied in industrial engineering to design lightweight and efficient components. Despite that, many techniques based on structural optimization return a digital model that is far from being directly manufactured, mainly because of surface noise given by spikes and peaks on the component. For this reason, mesh post-processing is needed. Surface smoothing is one of the numerical procedures that can be applied to a triangulated mesh file to return a more appealing geometry. In literature, there are many smoothing algorithms available, but especially those based on the modification of vertex position suffer from high mesh shrinkage and loss of important geometry features like holes and surface planarity. For these reasons, an improved vertex-based algorithm based on Vollmer’s surface smoothing has been developed and introduced in this work along with two case studies included to evaluate its performances compared with existent algorithms. The innovative approach herein developed contains some sub-routines to mitigate the issues of common algorithms, and confirms to be efficient and useful in a real-life industrial context. Thanks to the developed functions able to recognize the geometry feature to be frozen during the smoothing process, the user’s intervention is not required to guide the procedure to get proper results.

Keywords: Additive manufacturing | Mesh processing | Structural manufacturing | Surface smoothing | Topology optimization

Abstract: Fused Deposition Modeling (FDM) 3D printing is the most widespread technology in additive manufacturing worldwide that thanks to its low costs, finished component applications, and the production process of other parts. The need for lighter and higher-performance components has led to an increased usage of polymeric matrix composites in many fields ranging from automotive to aerospace. The molds used to manufacture these components are made with different technologies, depending on the number of pieces to be made. Usually, they are fiberglass molds with a thin layer of gelcoat to lower the surface roughness and obtain a smooth final surface of the component. Alternatively, they are made from metal, thus making a single carbon fiber prototype very expensive due to the mold build. Making the mold using FDM technology can be a smart solution to reduce costs, but due to the layer deposition process, the roughness is quite high. The surface can be improved by reducing the layer height, but it is still not possible to reach the same degree of surface finish of metallic or gelcoat molds without the use of fillers. Thermoplastic polymers, also used in the FDM process, are generally soluble in specific solvents. This aspect can be exploited to perform chemical smoothing of the external surface of a component. The combination of FDM and chemical smoothing can be a solution to produce low-cost molds with a very good surface finish.

Keywords: Carbon fiber mold | Chemical smoothing | FDM | PVB | Vapor smoothing

Abstract: This study shows an application of the Design for Six Sigma (DFSS) Methodology in the field of medical engineering. This research aims to demonstrate the application of a systematic design approach in the development of the “Ocane”, an innovative concept of smart cane for visually impaired patients which was thought of in answer to the end user’s needs, deploying an easy to transport, locate, and adjust element with ultrasonic sensors and tactile feedback. DFSS is an analytical design methodology meant to organize project workflow in a sequence of specific steps. Other standardized design procedures such as Quality Function Deployment (QFD) and Stylistic Design Engineering (SDE) have been used to support DFSS in terms of targeting customer requirements and focusing on aesthetics for ergonomics analysis, respectively. First, the QFD process is introduced and applied to gather the final customer needs, completing the analysis with benchmarking and similar-thought products on the market. Afterwards, a description of the DFSS methodology and application to the case study was deployed. Thereafter, the SDE procedure is exposed by identifying the “Ocane” concept and development, and moving towards the completion of an inventive product with a creative design and careful attention to visually impaired clients’ requirements.

Keywords: Assistive technology | Blind people | Design | DFSS | QFD | SDE | Visually impaired | Walking cane

Abstract: The design of an E segment, executive, midsize sedan car was chosen to fill a gap in the market of the Ford brand and to achieve the goal of innovation looking towards the future. Ford has not owned an E-segment flagship sports sedan for years, since the historic 1960s Falcon. Starting from the latter assumption and considering that the major car manufacturers are currently investing heavily in E-segment cars, it is important to design a new model, which has been called the Eagle. This model proposed here is to fill the gap between Ford and other companies that are already producing sport cars for the electric sector and to complete Ford’s proposal. The presented methodology is based on SDE, on which many design tools are implemented, such as Quality Function Deployment (QFD), Benchmarking (BM), and Top Flop Analysis (TPA). A market analysis follows in order to identify the major competitors and their key characteristics considering style and technology. The results are used to design an innovative car. Based on the most developed stylistic trends, the vehicle is first sketched and then drawn in the 2D and 3D environments for prototyping. This result leads to the possibility of 3D printing the actual model as a maquette using the Fused Deposition Modelling (FDM) technology and testing it in different configurations in Augmented Reality (AR). These two final applications unveil the possibilities of Industry 4.0 as enrichment for SDE and in general rapid prototyping.

Keywords: Additive manufacturing | Augmented reality | Benchmarking | Car design | Design engineering | QFD | Stylistic design engineering (SDE)

Abstract: Nowadays additive manufacturing is affected by a rapid expansion of possible applications. It is defined as a set of technologies that allow the production of components from 3D digital models in a short time by adding material layer by layer. It shows enormous potential to support wind musical instruments manufacturing because the design of complex shapes could produce unexplored and unconventional sounds, together with external customization capabilities. The change in the production process, material and shape could affect the resulting sound. This work aims to compare the music performances of 3D-printed trombone mouthpieces using both Fused Deposition Modelling and Stereolithography techniques, compared to the commercial brass one. The quantitative comparison is made applying a Design of Experiment methodology, to detect the main additive manufacturing parameters that affect the sound quality. Digital audio processing techniques, such as spectral analysis, cross-correlation and psychoacoustic analysis in terms of loudness, roughness and fluctuation strength have been applied to evaluate sounds. The methodology herein applied could be used as a standard for future studies on additively manufactured musical instruments.

Keywords: Additive manufacturing | Design of experiment | Musical instruments | Sound analysis | Stereolithography

Abstract: Technology evolution and wide research attention on 3D printing efficiency and processes have given the prompt need to reach an understanding about each technique’s prowess to deliver superior quality levels whilst showing an economical and process viability to become mainstream. Studies in the field have struggled to predict the singularities that arise during most Fused Deposition Modeling (FDM) practices; therefore, diverse individual description of the parameters have been performed, but a relationship study between them has not yet assessed. The proposed study lays the main defects caused by a selection of printing parameters which might vary layer slicing, then influencing the defect rate. Subsequently, the chosen technique for optimization is presented, with evidence of its application viability that suggests that a quality advance would be gathered with such. The results would help in making the FDM process become a reliable process that could also be used for industry manufacturing besides prototyping purposes.

Keywords: Defects | Optimization | Optimized FDM | Printing parameters | Void occurrence

Abstract: This paper describes a methodology to design and optimize a controllable pitch propeller suitable for small leisure ship boats. A proper range for design parameters has to be set by the user. An optimization based on the Particle Swarm Optimization algorithm is carried out to minimize a fitness function representing the engine’s fuel consumption. The OpenProp code has been integrated in the procedure to compute thrust and torque. Blade’s geometry and tables about pitch, thrust and consumption are the main output of the optimization process. A case study has been included to show how the procedure can be implemented in the design process. A case study shows that the procedure allows a designer to sketch a controllable pitch propeller with optimal efficiency; computational times are compatible with the design conceptual phase where several scenarios must be investigated to set the most suitable for the following detailed design. A drawback of this approach is given by the need for a quite skilled user in charge of defining the allowable ranges for design parameters, and the need for data about the engine and boat to be designed.

Keywords: CAD | Controllable pitch propeller | Design propeller | Particle swarm optimization

Abstract: Three-dimensional printed custom cutting guides (CCGs) are becoming more and more investigated in medical literature, as a patient-specific approach is often desired and very much needed in today’s surgical practice. Three-dimensional printing applications and computer-aided surgical simulations (CASS) allow for meticulous preoperatory planning and substantial reductions of operating time and risk of human error. However, several limitations seem to slow the large-scale adoption of 3D printed CCGs. CAD designing and 3D printing skills are inevitably needed to develop workflow and address the study; therefore, hospitals are pushed to include third-party collaboration, from highly specialized medical centers to industrial engineering companies, thus increasing the time and cost of labor. The aim of this study was to move towards the feasibility of an in-house, low-cost CCG 3D printing methodology for pediatric orthopedic (PO) surgery. The prototype of a femoral cutting guide was developed for its application at the IOR—Rizzoli Orthopedic Institute of Bologna. The element was printed with an entry-level 3D printer with a high-temperature PLA fiber, whose thermomechanical properties can withstand common steam heat sterilization without bending or losing the original geometry. This methodology allowed for extensive preoperatory planning that would likewise reduce the overall surgery time, whilst reducing the risks related to the intervention.

Keywords: 3D printing | CAD surgery simulation | CASS | CT scan | Cutting guide | Orthopedic reproduction model

Abstract: The present study aims to validate a new research method called IDeS (industrial design structure) through the design of an electric bicycle for everyday city life. IDeS is the latest evolution of a combination of innovative and advanced systematic approaches that are used to set a new industrial project. The IDeS methodology is sequentially composed of quality function deployment (QFD), benchmarking (BM), top-flop analysis (TFA), stylistic design engineering (SDE), design for X, prototyping and testing, budgeting, and planning. The present work illustrates how to integrate the abovementioned design methods and achieve a convincing result. In going through the IDeS method step by step, we compare the different solutions on the market in order to understand which are the best performing products and to understand what is missing on the market. This method allowed us to design a bicycle that is as close as possible to the “ideal bike”, obtained with the top/flop analysis.

Keywords: Benchmarking (BM) | Industrial design structure (IDeS) | Quality function deployment (QFD) | Stylistic design engineering (SDE) | Sustainable design | Sustainable mobility | Top-flop analysis (TFA)

Abstract: There is a looming shortage of well-trained professionals in the wood construction workforce. To challenge this shortage, we developed a simulated learning environment that leverages a novel Virtual Reality (VR) system to train novice workers in wooden wall construction. A comprehensive task analysis was first used to best identify training requirements. Then, a virtual building site was modeled and a 3D video tutorial was implemented using a VR Head-Mounted Display (HMD). To evaluate the effectiveness of this tool, participants who learned via the VR training tool were compared with participants who instead only had simple 2-D instructional video training. VR training resulted in better retention, task performance, learning speed, and engagement than the video training counterpart, maintaining system usability. This demonstrates that VR is a viable training tool for the construction sector and can produce benefits beyond those of traditional video training.

Keywords: Human-computer interaction | Virtual reality | Virtual training | Workforce development

Abstract: This experimental study defines the usage of a computer-aided surgical simulation process that is effective, safe, user-friendly, and low-cost, that achieves a detailed and realistic representation of the anatomical region of interest. The chosen tools for this purpose are state-of-the-art Computer Aided Design (CAD) software for mechanical design, and are the fundamental application dedicated to parametric modeling. These tools support different work environments, each one is for a specific type of modeling, and they allow the simulation of surgery. The result will be a faithful representation of the anatomical part both before and after the surgical procedure, screening all the intermediate phases. The doctor will assess different lines of action according to the results, then he will communicate them to the engineer who, consequently, will correct the antisymmetric issue and regenerate the model. Exact measurements of the mutual positions of the various components, skeletal and synthetic, can be achieved; all the osteosynthesis tools, necessary for the surgeon, can be included in the project according to different types of fracture to perfectly match the morphology of the bone to be treated. The method has been tested on seven clinical cases of different complexity and nature and the results of the simulations have been found to be of great effectiveness in the phase of diagnosis and of preoperative planning for the doctors and surgeons; therefore, allowing a lower risk medical operation with a better outcome. This work delivers experimental results in line with theoretical research findings in detail; moreover, full experimental and/or methodical details are provided, so that outcomes could be obtained.

Keywords: 3D processing | CAD-aided | Customized surgery | Pediatric orthopedics | Preoperative planning | Surgical simulation

Abstract: The study of CAD (computer aided design) modeling, design and manufacturing techniques has undergone a rapid growth over the past decades. In medicine, this development mainly concerned the dental and maxillofacial sectors. Significant progress has also been made in orthopedics with pre-operative CAD simulations, printing of bone models and production of patient-specific instruments. However, the traditional procedure that formulates the surgical plan based exclusively on two-dimensional images and interventions performed without the aid of specific instruments for the patient and is currently the most used surgical technique. The production of custom-made tools for the patient, in fact, is often expensive and its use is limited to a few hospitals. The purpose of this study is to show an innovative and cost-effective procedure aimed at prototyping a custom-made surgical guide for address the cubitus varus deformity on a pediatric patient. The cutting guides were obtained through an additive manufacturing process that starts from the 3D digital model of the patient’s bone and allows to design specific models using Creo Parametric. The result is a tool that adheres perfectly to the patient’s bone and guides the surgeon during the osteotomy procedure. The low cost of the methodology described makes it worth noticing by any health institution.

Keywords: 3D Printing | CAD Modeling | Cutting guides | Pediatric orthope-dics | Preoperative simulation | Surgery and diagnostics

Abstract: A numerical investigation is conducted in order to identify a PID control loop feedback scheme able to return dynamics augmentation and superior seakeeping characteristics in the application of high speed flying yacht hulls. An existing lumped parameters model based on general unsteady equations of motion is extended and implemented in combination with a regular basic ocean waves model, to conduct parametric studies and predict the overall performances of a specific engine-propelled flying yacht hull, both in calm and rough water conditions. The unsteady behavior of six foiling/maneuvering appendages is investigated, the hydrodynamic characteristics being based on a database generated through the use of computational fluid dynamics methods (CFD) coupled with static/dynamic-mesh schemes. Equations of motion and hydrodynamics are solved numerically by explicit time-integration method. By comparison with control open-loop conditions, the results show the effects of the use of PID controllers in such dynamic systems in terms of seakeeping performances and dynamics augmentation.

Keywords: Flying yacht | Foiling | Hydrodynamic performances | Lumped parameters model | Ocean waves | PID control

Abstract: The work carried out has the purpose of improving and optimizing various industrial technical operations, such as preventive maintenance, taken here as an example of application, using the Design for Disassembly (DfD) technique. Therefore, through four metaheuristic methods that have been chosen among the most widespread in the field (described below) to make a comparison between them, the optimal disassembly sequence is sought, if it exists, in terms of time and then costs in order to extract a target component without damaging the other mechanical parts of the assembly. The hypothesis that has been tested throughout this case study is “a responsible application of DfD, not only from the design process of a product but also during the disassembly procedure, can bring substantial benefits to the company”. Interaction with a hypothetical operator in charge of the work to be performed is implemented with the use of augmented reality. In fact, through an application programmed for an Android device (in this case, a mobile phone, hence a handheld device), the operator can be instructed step-by-step on the disassembly sequence in dynamics as an animation. Finally, two virtual buttons were added in augmented reality with which the operator can start and pause/resume the animation at any time to facilitate the understanding of the different steps established by the sequence.

Keywords: Augmented reality | CAD | DFD | Industrial maintenance | Optimization

Abstract: Software for image analysis endorsed further developments in the medical area that would accept state of the art reengineering processes to reproduce actual internal organs and structures of the human body. Previous research on FDM produced elements in the medicine field shown important discoveries on orthopedics. Preoperative planning shown to be suitable for additive manufacturing solutions that could help to improve the efficiency on procedures lowering potential risks after surgery. Accurate and well thought planning is necessary to choose the best way for the practice and deliver the best results. Tooling customization has shown to help into achieving this result. Bone-related surgeries require customized cutting guides for better accuracy. The following work aims to deliver the opportunity to use variations of Polylactic acid (PLA) based cutting guides in actual surgery practices by means of sustaining a regular heat-sterilization procedure without compromising its tailor-made characteristics. This would be possible by means of a proved, reliable procedure for obtaining the prototype from traditional CT scan images. As a result, HTPLA material composition and crystallization properties allowed to sustain a sterilization procedure in a way that does not compromise the reliability of the part, nor the safety of the procedure, so prototypes made with a similar process as the proposed one, can be used in actual surgery practices with safety.

Keywords: 3D Engineering | Cutting Guide | FDM | HTPLA | Sterilization

Abstract: This work shows a preoperative simulation procedure with Computer Aided Design (CAD) 3D software for a patient suffering from Ollier's disease. This pathology is very rare and occurs in extremely different ways depending on the case. Consequently, it is difficult to establish a correct surgical strategy that can be applied in a similar way to all patients. Computer Aided Surgical Simulation (CASS) process uses advanced modeling technologies to reproduce bony anatomy and simulate the surgery. The starting point is represented by the 3D digital model of the bone obtained from tomographic images. Through CAD modeling software such as Creo Parametric and following surgeons directives, engineers can provide doctors with orthopedic simulation and expectation of achievable surgical outcome. If virtual surgical prediction doesn’t meet doctors requirements, model is regenerated and it is possible to seek for a better solution. CASS process allow for extensive surgical planning, enhancing accuracy in theatre and enriching the amount of medical information that is needed to perform complex orthopedic procedures. In conclusion, the possibility to recognize in advance the overall orthopedic situation and outcoming expectancy represent an extraordinary upgrade of current surgical state of the art, leading to minimally invasive surgeries and patient-specific solutions.

Keywords: 3D modeling | CAD | CASS | Parametric software | Preoperative planning

Abstract: This paper aims to provide the study of a design strategy for 3D printing production process, given its recent development, as well as that of high-performance materials. In particular, we focus on the blade of a wind generator by evaluating new construction methods deriving from new design approaches. The strategies used for the present study are described as follows: firstly, it was necessary to proceed to redesign the blade, by CAD software in order to menage a 3D model for the study and to initialize the whole project; then, the FEM analysis to validate the study. Finally, the AM (Additive Manufacturing) theorization and simulation for both a scaled blade and a full-sized one. The motivation behind this paper draws on the predominance and the constant evolution of the 3D printing in recent years, as well as the continuous research on both development and improvement of costs and performance of composite materials used.

Keywords: Composite Materials | Design for Additive Manufacturing | Finite Element Analysis | Wind-turbine

Abstract: This paper presents a study based on Design for Disassembly (DfD) applied to a hydraulic pump through the Disassembly Geometry Contacting Graph (DGCG) methodology. DfD is today very important to reduce the disposal or maintenance costs foreseeable already in the planning phase. One of the key points in reducing costs is reducing time for disassemble each component. Because of that, the disassembly time was considered respect to other fundamental and optimizable characteristics such as: Disassembly costs, operations to be performed, quantity of material, etc. All the operations have been evaluated using the time measurement units (TMUs). The objective of the paper is to minimize the disassembly times required for an operator to separate each single component from the other. The study of accessibility, positioning, strength, and basic time led to a comparison between different disassembly methods in order to produce the optimal sequence. In the end, the validation of the sequence was carried out in an Augmented Reality (AR) environment in order to predict the manual disassembly understanding the possible issues without the need of building the components. Using AR, it was possible to look at the assembly during the design phase in a 1:1 scale and evaluate the chosen sequence.

Keywords: CAD | Disassembly | Sequence | TMU | Virtual Reality

Abstract: In the last decade citizens mobility is changing towards a more environment-friendly, more flexible and more shared way of moving around the city. The objective, now, is to decrease the levels of pollution. Notwithstanding people mobility is based on rapidity, sustainability is becoming always more important. In order to follow the new needs of future customers, the present work is presenting a new approach to design in order to obtain an innovative product with the aforementioned characteristics. The new approach is to combine two innovative methodology to design: The first one is Design For Six Sigma (DFSS) and it is useful to structure the project into five main phases (Define, Measure, Analyze, Design, Validate), systematically; the second one is Stylistic Design Engineering (SDE) and it is dedicated to the aesthetic development of a new product following an engineering structure of all the phases of the work. DFSS and SDE will be applied in the present paper in order to give an answer to the arising problem of the new mobility of the future, providing for a new innovative urban means, matching the different characteristics of an hoverboard and of a kick-scooter. The output of the study, described along the paper, is the adaptability of the abovementioned methodologies and the proposal of a new product concept for the scopes illustrated.

Keywords: BENCHMARKING | DFSS | IDeS | QFD | SDE

Abstract: The present paper is about a family car project that starts from a study of the characteristics of the type of car taken into consideration and from an analysis of the environment carried out through an historical research on the models on the market from the 30s to the mid-90s, and their classification. The market analysis was carried out by answering six questions from the QFD and by developing the tables of relative importance and interrelation through which the most important and the most independent requirements to be attributed to the innovative family project were obtained. The competitor analysis was made through a research on the models currently on the market, the development of the benchmarking, and the what/how matrix from which the final requirements and project objectives were determined. The brand was selected, the budget was drawn up over a 12-month period and the car’s product architecture was defined. The SDE was carried out through an aesthetic analysis of the existing models, the sketches for each type of style and the selection of the final sketches. The development of the product, instead, consisted in the prototyping of a 1:18 scale model of the car through 3D printing.

Keywords: 3D Printing | CAD | QFD | Rendering | SDE

Abstract: Since 3D printing was developed, it became the most promising technique to speed up prototyping in a wide variety of areas across the industry. Rapid prototyping allows the medical industry to customize the surgery procedures, thus predicting its result. Biomedical applications made by medical grade elastic thermoplastic polyurethane (TPU); a non-traditional plastic material which allows to obtain additional benefits in rapid 3D prototyping because of its flexibility and anti-bacteriological capabilities. The aim of this study is to assess the efficacy of TPU polymer, FDM objects sourced from CT scanned 3D surfaces for helping surgeons in preoperative planning and training for increasing environment perception, that is, geometry and feeling of the tissues, whilst performing standard procedures that require complex techniques and equipment. A research was performed to assess the physical and qualitative characteristics of TPU 3D developed objects, by developing a proper SWOT analysis against PLA, a widely used, and cost-effective option in FDM industry. Therefore, giving a proposition opposite to other known modern medical planning techniques and bringing out the benefits of the application of TPU-sourced, FDM parts on professional medical training. As a result, PLA is a reliable, wide-available process whilst TPU’s flexible capabilities improves realism in 3D printed parts. Surgical planning and training with rapid prototyping, would improve accurate medical prototyping for customized-procedures, by reducing surgery times, unnecessary tissue perforations and fewer healing complications; providing experience that other FDM materials like PLA cannot be reached.

Keywords: 3D Printing | 3D Scanner | QFD | Surgical Training | TPU

Abstract: Nowadays, the importance of the concept of “Urban Mining” is growing even more, which consists in searching for raw materials inside objects that have reached the end of their life, instead of “inside nature”. It can be commonly found especially in mechanical and electronic equipment valuable materials, which can be extracted and reused as secondary raw materials. The importance of Design for Disassembly (DfD), that is the central topic of this paper, is increasing because of it brings great advantages in terms of disassembly times of components that have reached the end of life. According to the Disassembly Sequence Planning (DSP), this paper presents an application of several methods derived from literature to a two-way valve, to find optimal disassembly sequences. Different sequences have been compared in terms of disassembly time consuming, by the conversion of operations into disassembly time using accredited methods found in literature. Finally, an application in Augmented Reality is proposed to simulate a practical evaluation of what has been theorised so far.

Keywords: Augmented Reality | CAD modelling | Design for Disassembly | Sequence Planning

Abstract: This work aims to present the application of mechanical modeling software in three dimensions in the medical field, analyzing the procedures used by the engineer to support the orthopedic surgeon in preoperative planning. The first step of the procedure involves CT examinations in patients selected for surgery: DICOM images are managed in post-processing to obtain multiplanar reconstructions of the bone lesion to be treated. The files are then optimized, made shareable and imported into CREO's work platform; this is part of a family of CAD software products for mechanical design, developed by PTC, and is the fundamental application dedicated to parametric modeling. The result will be a faithful representation of the anatomical part both before and after surgical procedure, screening all the intermediate phases. The doctor will assess different lines of action according to the results, than he will communicate them to the engineer who, consequently, will correct and regenerate the model. The method finds its power in the dialogue between engineer and doctor: In complex cases closer collaboration is needed while, for the evaluation of less demanding injuries, the exam could be assigned as a remote project which, once completed, is returned to the medical facility of competence.

Keywords: 3D modeling | Computer aided | Parametric software | Preoperative planning | Surgical simulation

Abstract: Fused Deposition Modeling (FDM) 3D printing technology has widespread in a variety of scientific fields, since rapid prototyping and low-cost investments well meet flexibility of application. Mechanical engineering is taking an essential role in Orthopaedics and Traumatology. As a patient-specific approach and minimally invasive surgeries are progressively needed in today’s medical routines, highly-customized 3D printed devices and surgical instruments represent a milestone in medical equipment. Virtual preoperatory planning and computer aided surgical simulations (CASS) enhance 3D visualization of human anatomy, giving doctors full understanding of traumas and deformities. Custom cutting guides (CCGs) represent the cutting edge of patient-dedicated surgical routines, allowing for a sensible reduction of operative time and risk of human error. While maxillofacial surgery (MFS) has already adopted customized 3D printed tools, pediatric orthopaedics (PO) and general long bones surgery strive to put these devices into common practice. Limitations to a large-scale implementation rely on collaboration with the industrial world, as engineering and designing skills are inevitably demanded. Here displayed is the prototype for a femoral cutting guide designed for a pediatric application of the IOR - Rizzoli Orthopaedic Institute of Bologna. The device was printed in a High-Temperature PLA, supporting common steam heat sterilization and maintaining designed geometry.

Keywords: 3D printing | CAD surgery simulation | CT scan | Cutting guide | Orthopaedic reproduction model

Abstract: The present work is a case study about the application of the methodology named Stylistic Design Engineering (SDE), that is an approach to develop car design projects in the industrial world. For attending this goal, it was chosen the S-segment car products, category that identifies the sport car as today’s Lotus. The inspiration for the project started from the top model in the past years of the car manufacturer Audi, or the Audi Quattro (1980-1991). This model represented all the time the most advanced technology in the automotive world of the house, and the most important thing was the all-wheel drive, therefore with four-wheel drive. In the following pages will be illustrated the summary of the path that led to the final product following the “instructions” of SDE method.

Keywords: 3D Printing | QFD | SDE | Sportcar

Abstract: This work is the outcome of a partnership between the Department of Industrial Engineering of the University of Bologna and the Rizzoli Orthopedic Institute of Bologna. The aim of this collaboration is using medical engineering tools during orthopedic surgeries. This article focuses on the design and construction of a custom-made surgical guide for cubitus varus. The guides are special aids that allow surgeons to perform operations smoothly, to achieve the planned result and to reduce the risk of inaccuracy. They are obtained with an additive manufacturing process that starts from a 3D digital model of the patient's bone obtained from CT scans and allow designing patient-specific templates using specific software as the Creo Parametric CAD. For the proper functioning of the guide the internal shape must correspond to the external profile of the patient's bone. In this way, the tool obtained fits exactly to the bone and it is possible to direct the cutting during surgery in a very specific direction as identified in the preoperative planning phase.

Keywords: 3D Printing | Cutting guides | Pediatric Orthopedics | Surgery and Diagnostics

Abstract: This paper presents a project proposal about the design of an innovative and futuristic transport system that aims to replace highways and major roads with a fast, safe and ecological new arrangement. The aim was to conceive an innovative new infrastructure of transport that fits into a future city scenery. In the current historical period we are invested by fast, frenetic and unstoppable evolution that leads to the continuous replacement of products and technologies that in a few years went from being innovative to become obsolete and outdated. Moreover, this process has inevitably affected the whole world of transport: It has assisted and is still witnessing the replacement of diesel and petrol engines with hybrid and electric ones. These evolution and change have led us into the research and understanding of increasingly innovative technologies such as the ones with zero impact motors or magnetic levitation, which in the near future will probably become a valid alternative, or even the new pioneers of transport around the world. At the beginning, the methodology used for the present case study was adopted to analyze how people used to move in the current period (i.e. 2019-20); then, it was taken into consideration the problems linked to the main means of transport diffused, with clean and green technologies; later, it was carried out a market analysis for each category, with related Benchmarking, in order to find the most significant technical characteristics of each one. According to the emerged results, a concept of an innovative transport system was developed, in order to guarantee the safety and privacy of passengers in addition to other performance items, as high speed or integration with other means. The intention was to create a transport network that could connect many cities with direct and easily practicable routes that could replace highways.

Keywords: Ecological | Future city | Future transport | High Speed | Magnetic Levitation | Safe

Abstract: In the present work the Stylistic Design Engineering (SDE), a structured engineering methodology developed to carry out car design projects, is applied to the creation of a new reliable and robust utility vehicle, also suitable for traveling in the countryside. In particular, the design project aimed at the possibility of launching a new Citroen 2CV that would maintain the lightness and reduced fuel consumption of the previous model but that would combine these characteristics with greater eco-sustainability, thanks to electric drive, and greater comfort for passengers. SDE consists of the following steps: (1) sketches; (2) 2D CAD drawings; (3) 3D CAD models; (4) 3D printed models (also referred to as styling models); (5) Optimization of maquettes through technical objectives. This project deals with the exterior restyling of the Citroen 2CV and was carried out using different technologies and design methodologies that will be further explained in detail, such as the Pininfarina method, the QFD (Quality Function Deployment) and the 6 Sigma method. The work was organized in different phases and in all these phases the quality methodologies mentioned above were used. At first the Citroen style was studied, a fundamental step to better understand the characteristics of the brand and also the main characteristics carried out over the years of the product's life. Subsequently, the freehand sketching phase was carried out, inspired by the considerations made in the previous study phase. This phase continued until a satisfactory form was found by analyzing and discarding the various proposals of the various types of style. Once the definitive proposal was chosen, the definitive three-dimensional shape was obtained and on it it was possible to evaluate proportions and dimensions, also thanks to the rendering software.

Keywords: Benchmarking Analysis | Car Design | Quality Function Deployment (QFD) | Stylistic Design Engineering (SDE) | Top Flop Analysis

Abstract: The life of industrial products is getting shorter due to the rapid evolution of technologies. Because of that, the creation of models that are interested in last part of the product’s life are becoming extremely relevant. In recent years, many investments have been made in the recycling of raw materials and the reuse of End-Of-Life (EOL) products in order to reduce the waste of resources. Strategies of Design for Environment (DfE) have been searched and, for this reason, the Design for Disassembly (DfD) has become a fundamental phase in the product life cycle with the subsequent creation of design techniques aimed precisely at disassembly. Using this methodology, the designer can study and plan the optimal sequence which should be based on countless factors and criteria because there is not a straightforward path or a single combination of operations to follow. This paper describes and compares multiple disassembly methods based on minimum disassembly time with reference to a worm gear reducer. In particular, the component was made entirely on CAD (SolidWorks) and the sequences were pplied in a virtual environment. In this way, it was possible to evaluate different algorithms and obtain the optimal disassembly sequence that minimize the overall disassembly time.

Keywords: CAD | Disassembly | Sequence | TMU | Virtual Reality

Abstract: Beginning from an analysis of all the top types of execution of the hoverboard, a contemporary vehicle for city transportation, inventive concepts were generated to design it. Quality-oriented methodology, just like Quality Function Deployment (QFD) for example, contributed the desires to start from, while through an innovation-oriented methodology, just like Teorija Rešenija Izobretatel'skich Zadač (TRIZ) method, proposals and notions for innovative settings were reached. In practice, while the QFD methodology has a powerfully conceptual appeal, and it is the basis of our analysis, the TRIZ method gives a more innovative thrust and deals the aspects that are strongly constructive and concrete. The matrix of contradictions has been used within the Hill model, and through it, it has been possible to rework the innovative problems, suggested by the analysis of the QFD, in terms of technical contradictions. The main purpose of the following work is to demonstrate how the two methodologies mentioned above, namely the QFD methodology and the TRIZ methodology, can be integrated within a path of development of innovative products, supporting one for the other.

Keywords: contradictions | innovative solution | QFD | TRIZ | urban transportation systems

Abstract: Smoothing algorithms are used for mesh refinement and to remove undesired surface. This numerical procedure is recommended and applied on triangulated file coming from 3D scanners or Topology optimization designs based on voxel representation before the optimized structure is manufactured by Additive Manufacturing technologies. In literature, there are several available algorithms, but many of them suffer from mesh shrinkage and do not give to the designer easy procedures to select regions which do not need the application of the smoothing procedure as holes or flat surfaces. For this reason, an improved vertex-based algorithm is presented in this work along with a case study to prove its performances compared with existent algorithms. The algorithm confirms to be efficient and useful. However, user's intervention is required to guide the procedure to get proper results.

Keywords: mesh fairing | mesh smoothing | topology optimization | voxel

Abstract: In this work, a structured design method, the Stylistic Design Engineering (SDE), is applied for the construction of a new minivan car, in particular a new city car, which we will call FIAT 600 Omega. The SDE, or Stylistic Design Engineering, is a structured engineering method for carrying out automotive design projects. The SDE method consists of six different phases: (1) Analysis of stylistic trends; (2) Sketches; (3) 2D Computer Aided Design (CAD) drawings; (4) 3D CAD models; (5) Rendering; (6) Solid stylistic model (also called style maquette). This project deals with the external redesign of the Fiat 600 multiple, a small minivan which was very successful in the 1950s and 1960s. SDE is a methodology consisting of various technologies and design methodologies that will be further explained in detail, such as the Pininfarina method, the Quality Function Deployment (QFD) method, Benchmarking (BM), and Top Flop Analysis (TPA). The work was organized according to the different phases. Initially, the Fiat style was studied, in particular the style of the FIAT 600 MULTI PURPOUSE VEHICLE (MPV). This step is essential to better understand the characteristics of the brand and also the main characteristics carried out over the decades. Then we moved on to the freehand sketching phase, based on what we learned in the previous phase of the study. When a satisfactory shape was found for the new car, by analyzing and discarding the different proposals of the various types of style, we proceeded to the evaluation of the proportions and dimensions through two-dimensional drawings and finally we obtained the three-dimensional shape of the new car thanks to 3D CAD software and rendering software. Many advantages in the industrial world SDE takes together with its development. In fact, until the early 2000s, car design and styling was considered quite a craft activity, not a technical or scientific one, mostly based on the great capability of famous car designers and masters, just like Giugiaro, Zagato, Bertone, Pininfarina, Stephenson, Bangle, etc. Then, thanks to the industrial activity of Eng. Lorenzo Ramacciotti, former CEO of Pininfarina Spa and Mechanical Engineer, and also thanks to the academic studies developed at ALMA MATER STUDIORUM University of Bologna, SDE became the object of attention, because it is able to systematize the car design process and reduce costs. With SDE, a good design research or an industrial product development team can complete a car design project, also without the presence of a mentor. Car Design Process finally becomes with SDE a scientific method; Car Design becomes with SDE an industrial method. Industrial needs are nice products made in a short time; SDE is structured to attend these issues. Industrial challenges follow innovation, in shape and functionality; SDE is able to recognize innovation. Industrial benefits can be reached with SDE, ensuring beautiful aesthetic projects are realized systematically and with low costs.

Keywords: Benchmarking | Car design | Citycar | Design engineering | QFD | Stylistic design engineering (SDE) | Topflop analysis

Abstract: This work aims to present an in-house low-cost computer-aided simulation (CASS) process that was recently implemented in the preoperative planning of complex osteotomies for limb deformities in children. Five patients admitted to the Unit of Paediatric Orthopaedics and Traumatology from April 2018 to December 2019, for correcting congenital or post-traumatic limb deformities were included in the study. Three-dimensional (3D) digital models were generated from Computed Tomography (CT) scans, using free open-source software, and the surgery was planned and simulated starting from the 3D digital model. 3D printed sterilizable models were fabricated using a low-cost 3D printer, and animations of the operation were generated with the aim to accurately explain the operation to parents. All procedures were successfully planned using our CASS method and the 3D printed models were used during the operation, improving the understanding of the severely abnormal bony anatomy. The surgery was precisely reproduced according to CASS and the deformities were successfully corrected in four cases, while in one case, the intraoperative intentional undersizing of the bone osteotomy produced an incomplete correction of a congenital forearm deformity. Our study describes the application of a safe, effective, user-friendly, and low-cost CASS process in paediatric orthopaedics (PO) surgery. We are convinced that our study will stimulate the widespread adoption of this technological innovation in routine clinical practice for the treatment of rare congenital and post-traumatic limb deformities during childhood.

Keywords: 3D modeling | Computer aided | Osteotomy | Paediatric orthopaedics | Preoperative planning | Surgery | Surgical simulation

Abstract: This work aims to analyze the characteristics and importance that design techniques for disassembly assume in the modern design phase of a mechanism. To this end, the study begins by considering a three-dimensional model of a gear motor, taken from the components of which the overall drawings are arranged and from the relief of those not available. Once the mechanism has been digitally reconstructed, the activity focuses on the study of the optimal disassembly sequence by comparing different methodologies, according to two evaluation criteria-minimizing the time taken and minimizing the number of tool changes necessary to complete the sequence. The main results of the work are (1) defining a standard methodology to improve disassembly sequence planning, (2) finding the best disassembly sequence for the specific component among the literature and eventually new methods, and (3) offering to the industrial world a way to optimize maintenance operations in mechanical products. Referring to the limitation of the present works, it can be affirmed that the results are limited to the literature explored and to the case study examined.

Keywords: CAD | Disassembly sequence planning | Globoid gear motor

Abstract: Purpose: The purpose of this study is the evaluation of advantages and criticalities related to the application of addtive manufacturing (AM) to the production of parts for musical instruments. A comparison between traditional manufacturing and AM based on different aspects is carried out. Design/methodology/approach: A set of mouthpieces produced through different AM techniques has been designed, manufactured and evaluated using an end-user satisfaction-oriented approach. A musician has been tasked to play the same classical music piece with different mouthpieces, and the sound has been recorded in a recording studio. The mouthpiece and sound characteristics have been evaluated in a structured methodology. Findings: The quality of the sound and comfort of 3D printed mouthpieces can be similar to the traditional ones provided that an accurate design and proper materials and technologies are adopted. When personalization and economic issues are considered, AM is superior to mouthpieces produced by traditional techniques. Research limitations/implications: In this research, a mouthpiece for trombone has been investigated. However, a wider analysis where several musical instruments and related parts are evaluated could provide more data. Practical implications: The production of mouthpieces with AM techniques is suggested owing to the advantages which can be tackled in terms of customization, manufacturing cost and time reduction. Originality/value: This research is carried out using a multidisciplinary approach where several data have been considered to evaluate the end user satisfaction of 3D printed mouthpieces.

Keywords: Additive manufacturing | Dental materials | Fused deposition modelling | Musical instruments | Stereolithography

Abstract: Nowadays technology is extensively used as aid for cooking activities and humans are relying on it for a wide range of tasks in their everyday life, making the cooking activity more effective, less time consuming and even accessible to less skilled people. The present work is a case study on the application of the Design for Six Sigma (DFSS) methodology that here is exploited for the realization of the so-called “food processor”. This device requires only electricity, it is able to cook, mix, chop up and steam, allowing the user to obtain tasty and well-controlled dishes through simplified procedures. The method used looks at what is already available on the market enabling to design an innovative product while fulfilling customer requirements. QFD analysis and Benchmarking analysis were used as a support for the method. The result of the research is the design of an innovative food processor, where the design procedure has been guided by DFSS methodology and has been implemented through Creo Parametric software.

Keywords: Benchmarking Analysis | Design for Six Sigma (DFSS) | Food Processor | Quality Function Deployment (QFD)

Abstract: Sustainable mobility means a series of services and means of transport designed to reduce traffic, improve air quality and cut energy consumption; it is essential to integrate the various transport systems and encourage the spread of electric vehicles. The European Commission proposes new targets for average CO2 emissions to accelerate the transition to low-emission vehicles. The goal is to reduce emissions by 40% by 2030, in line with the Paris agreements. It is not only a question of replacing private means of transport, but also of encouraging the development of new business models and more efficient use of public and freight transport. The present paper works on six main points: • New standards that help manufacturers to innovate and offer low-emission vehicles on the market • Solutions for sustainable mobility in public systems • Investments for the diffusion of infrastructures for alternative fuels • Revision of the combined transport directive which promotes the use of different means for freight transport • Development of long distance bus connections across Europe • Development of better and better batteries The diffusion of micro-mobility systems requires a general change of context. The city must keep up with technology and become smart, the regulations and all sharing phenomena must be adequate. In 2020, 80 billion objects connected to the world through 1200 satellites are estimated: urban mobility will be greatly influenced and will become a connecting element between the environment and those who live in it. The micro-mobility market in Europe could reach 150 billion dollars by 2030. As the possibilities for use increase, the number of startups for mobility sharing also increases. It is estimated that at the end of 2018 there were 5.2 million subscribers to at least one of the sharing services active in the area, one million more than the previous year. In particular, this project aims to propose an innovative, sustainable and ecological means of transport suitable for everyone and which can be a valid alternative for getting around the city.

Keywords: Benchmarking Analysis | Industrial Design Structure (IDeS); Car Design | Quality Function Deployment (QFD) | Stylistic Design Engineering (SDE); future mobility

Abstract: This paper presents a design proposal of a future family car. The target audience of this application are families with children, so that different customer needs must be satisfied, like as good performances, reliability, spaciousness, eco-sustainability, safety and regulations for infants. The reference segment of the family car is the C / E of the Stan-dards ISO 3833: 1977. The first methodology used in this paper is the QFD, to determine the fundamental characteristics of our proposal. Then, with a Benchmarking analysis, we highlighted the most advantageous – top – and most disadvantageous – flop – solutions in terms of our product. The brand that emerged as the most suitable to meet the most influential characteristics from a customer perspective is Volkswagen. Subsequently, we proceeded using the tool of the SDE. Some features of different stylistic trends have been analyzed and merged to present our 7-seats, 4-wheel drive and 2-volume family car proposal, named “T-Golf”.

Keywords: Benchmarking Analysis | Car Design | Quality Function Deployment (QFD) | Stylistic Design Engineering (SDE)

Abstract: The work presented is a case study about the application of the methodology named Design For Six Sigma, which involves the concepts of Benchmarking and QFD analysis, applied to different devices/appliances, without having the target of the creation of a specific final product, but trying to outline a prototype of an innovative domotic house, where every device is connected to the main network and can communicate with the others. Four categories of products were analyzed: robot vacuum cleaner, smart refrigerators, domotic ovens and robot lawnmowers. Today these devices are very smart and technologically advanced but cannot co-operate for the realization of a connected system; which could happen thanks to the increasing use of Google Home and Amazon Alexa devices. In the following pages will be illustrated all the process described above comprehensive of the house project realized on SolidEdge and rendered on KeyShot.

Keywords: Benchmarking | Design For Six Sigma | Domotics | House of quality | QFD

Abstract: Given the general subject “Automotive Design” as starting point of the research, it was decided to focus the present paper on a particular segment of cars: the A segment, which is usually known as City Car. Before even starting to research about the City Car world, it was scheduled the work phases in a general way and after that, organizing time week by week to be sure it wouldn’t be run out of time before the complete ending. A Road Map was used as a graphic method to better visualize the path to follow during the project, in order to stay focused and always know and be ready for the next step. Two major moments were identified: a project set up, followed by the project development. The Project Set Up includes some preliminary analysis, to better understand the environment in which it is operating, only then it was be able to start focusing on the concept for our new car. Once defined the entire concept, and all the requests that should be to satisfied, the budget was outlined, instrument needed to cover the costs of design and production of the entire car. The Project Set Up comes to an end after the last phase of styling, which include a series of propositions concerning the aesthetic of the shell. Next, the developing of the project was taken on. This phase includes the 3D modelling via software, followed by the optimization of the model concerning the aerodynamic and the overall form. Once all the details concerning the 3d model were defined, it was time to proceed on prototyping the entire car via additive manufactory.

Keywords: Benchmarking Analysis | Industrial Design Structure (IDeS); Car Design | Quality Function Deployment (QFD) | Stylistic Design Engineering (SDE)

Abstract: This work is focused on the study of 3D prints applied in the orthopedic-pediatric field. The focus is therefore on all the processes that lead to obtaining 3D bone printing starting from the three-dimensional digital CAD model. Specifically, the case study concerns patients with flat foot pathology from tarsal synostosis. The final result of the printing process is a three-dimensional bone model reflecting the original anatomical structure. This is a useful tool for surgeons who can carry out a preventive analytical evaluation of the relative intervention methods. 3D printing can be useful both in the preoperative planning phase and during the operation. Depending on the case, it may be more convenient to use one material than another. For this reason, another goal set by this work concerns the study of materials used for 3D printing of bones.

Keywords: 3D Printing | Diagnostics | Pediatric Orthopedics | Surgery

Abstract: High-Speed Trains are defined as the “transport of the future” thanks to three main characteristics: safety, capability and sustainability. It is an environment friendly solution because it relies on electric energy, which can be fully produced from renewable sources, and it pollutes less compared to other transport systems. In fact, in comparison with automobiles and airplanes, High-Speed Trains generate 9 and 6 times less carbon dioxide respectively; and in terms of consumption per kilometer, it consumes respectively 6 and 4 times less. The first ever High-Speed Train was born in Japan and it began service in 1964 under the name of “Shinkansen”. The Japanese railway system has proved throughout history the efficiency and safety of this solution, becoming a model for the development of high-speed networks in other countries. Train designs vary depending on existing railways, geography and market requests. Bogies were born as simple supports for the coaches, provided with wheels and brakes, but with technological innovations, modern models contain electric engines, sensors and security devices. In this work, a new bogie was proposed following the rules of Design for Six Sigma (DFSS), which holds the main advantages of the models provided on the current market by the competitors.

Keywords: Design Engineering | Design for Six Sigma (DFSS) | High-Speed Train | Train Design

Abstract: The present work shows how 3D models extracted from a computerised tomography (CT) scan can be processed to be 3D printed into 1:1 orthopedic scale models, which find unquestionable utility in pre-operative surgical planning. Relying on the CAT-CAD methodology, which produces a 3D surface called “mesh” from diagnostic images of body parts, the CAD-AM process elaborates a volumetric bone model which a cost-efficient FDM printer can work with. The suitable materials for these applications are PLA polymers, due to their thermo-mechanical properties, affordability and ecological sustainability; these anatomic 3D printed models allows surgeons to accurately see bones injuries and trauma, resulting in a minimisation of risk and a much more flowing doctor-patient communication. Furthermore these 3D printed objects can be manufactured with specific density in order to simulate bone tissues, resulting in a useful tool through which experienced surgeons can pass on their knowledge to medical students at a very reasonable cost, overcoming the glaring limitations of two-dimensional images provided by CT scans. Here represented is a 3D printed 1:1 scale model of a femur donated to the Bone Bank of IOR-Rizzoli Orthopaedic Institute in Bologna.

Keywords: CT scan | FDM printer | Orthopaedic Reproduction Model | PLA polymer

Abstract: The interest of industrial companies for the Additive Manufacturing (AM) technology is growing year after year due to its capability of producing components with complex shapes that fit industrial engineering necessities better than traditionally manufactured parts. However, conventional Computer-Aided Design (CAD) software are often limited for the design and representation of complex geometries, especially when dealing with lattice structures: these are bio-inspired structures composed of repeated small elements, called struts, which are combined to shape a unit cell that is repeated across a domain. This design method generates a lightweight but stiff component. The scope of this work is to analyse the problem of the lattice structures representation in 2 D technical drawings and propose some contributions to support the development of Standards for their 2 D representation. This work is focused on the proposal of rules useful to represent such hierarchic structures. Python language and the open-source software FreeCad™ are used as a software platform to evaluate the suitability and usability of the proposed representation standard. This is based on simplified symbols to describe complex lattice structures instead of representing all the elements which constitute the lattice. The standard is thought to be used in technical 2 D drawings where assemblies are represented and lattice components are used (e.g. parts assembly, maintenance, parts catalogues). A case study is included to describe how the proposed standard could be integrated into a 2 D assembly drawing, following technical product documentation production typical workflow.

Keywords: Additive manufacturing | design | drawing standards | ISO standards | lattice structures

Abstract: Additive Manufacturing is becoming a suitable production process for many industries: it is based on the idea of adding material layer by layer, in opposite to traditional manufacturing processes. This technology shows advantages as design flexibility, internal logistics minimization and product customization that make it perfect to produce customized parts and all the applications where low production rates occur. The production of spare parts for classic or luxury cars is a field where Additive Manufacturing can be adopted because of low demand and relevant costs to manage stocks keeping several different parts in the after-sales inventory. The photogrammetry technique has been investigated to obtain the 3D model of the component to be replaced and send it to decentralized production centers equipped with 3D printers. This approach can enhance by far the supply chain management for automotive spare parts.

Keywords: Additive Manufacturing | Automotive | Maintenance | Photogrammetry | Supply chain management

Abstract: A significant growth of Additive Manufacturing technology has been noticed in the last few decades due to its well-established advantages. This production process based on the idea of adding material layer by layer, instead of removing it, has several advantages such as: time reduction in the design-to-manufacturing cycle, capability to produce complex shapes in a single piece thus reducing the connections, and weight saving just to mention the main significant. On the same wave of enthusiasm, the research community is significantly focused on this technology and many contributions that are focused on the whole range of aspects connected to this manufacturing way are already available. However, Additive Manufacturing is in a development phase, and the design tools, the material portfolio and the production methodologies are still far from the optimum typical of mature technologies. This paper critically reviews the Additive Manufacturing advantages and weaknesses which nowadays limits its wider application; a discussion about how these problems could be solved is included, together with an outlook of the challenges the practitioners must face off from nowadays up to a time window of ten years.

Keywords: Additive Manufacturing | Design tools | Future challenges | Technology review | Topological optimization

Abstract: Design for Assembly is a strategy of design aimed at minimising product cost through design and process improvements. It led to a revolution in the manufacturing industry, resulting in reduced product costs, improved quality, shorter time to market, lower inventory, fewer suppliers and many other improvements. DFA is the method of design of the product for ease of assembly and in this context this paper presents an application of the strategy to a virtual case study represented by a two-way relief valve modelled by CAD. The aim of this paper was to test some DFA methods proposed by the literature and search for an efficient assembly of the virtual two-way relief valve reproduced by CAD, then verifying its assembly effectiveness. Some evaluation methods proposed by literature about the optimisation of design efficiency have been applied to the case study and this led to reconsider the design of some parts of the product. A final new design for the valve is proposed and the evaluation methods applied have been tested again on the new solution, in order to validate the results. A comparison between the original valve and the new version proposed by the authors has been made, in order both to check the feasibility of the new valve and in order to check the evaluation methods proposed.

Keywords: CAD | DfA | Optimization

Abstract: The present study wants to bring to light a new type of crutch designed for a chronic patient with perennial limited mobility, who must use this support every time a move is needed. The main purpose of the project consists in recommending a correct use of the crutch through technology, limiting the damage normally caused by a bad use of crutches and giving a support both for the patient and for the doctor. All of the features of the crutches were defined through relationship matrices and a benchmarking, which helped us for defining the requirements; other important features were defined, taking a look to the technological progresses applied to new, patented crutches. The result is a sensorized crutch, functional and oriented to meet the user's needs in order to prevent an incorrect use of the support avoiding the growth of other pains.

Keywords: Analysis | Benchmarking | Crutch | Industrial Design Structure (IDeS) | Matrix of relative dependence | Matrix of relative importance | Medical prosthesis mobility | Patient | Project | Sensors | Tool

Abstract: This paper presents a a novel alghorithm of diagnosis and treatment of rigid flatfoot due to tarsal coalition. It introduces a workflow based on 3D printed models, that ensures more efficiency, not only by reducing costs and time, but also by improving procedures in the preoperative clinical phase. Since this paper concerns the development of a new methodology that integrates both engineering and medical fields, it highlights symmetry. An economic comparison is made between the traditional method and the innovative one; the results demonstrate a reduction in costs with the latter. The current, traditional method faces critical issues in diagnosing the pathologies of a limb (such as the foot) and taking decisions for further treatment of the same limb. The proposed alternative methodology thus uses new technologies that are part of the traditional workflow, only replacing the most obsolete ones. In fact, it is increasingly becoming necessary to introduce new technologies in orthopedics, as in other areas of medicine, to offer improved healthcare services for patients. Similar clinical treatments can be performed using the aforementioned technologies, offering greater effectiveness, more simplicity of approach, shorter times, and lower costs. An important technology that fits into this proposed methodology is 3D printing.

Keywords: 3D printing | Diagnostics | Orthopaedics | Paediatry | Surgery

Abstract: The paper broadly addresses how Industry 4.0 program drivers will impact maintenance in aviation. Specifically, Industry 4.0 practices most suitable to aeronautical maintenance are selected, and a detailed exposure is provided. Advantages and open issues are widely discussed and case studies dealing with realistic scenarios are illustrated to support what has been proposed by authors. The attention has been oriented towards Augmented Reality and Additive Manufacturing technologies, which can support maintenance tasks and spare parts production, respectively. The intention is to demonstrate that Augmented Reality and Additive Manufacturing are viable tools in aviation maintenance, and while a strong effort is necessary to develop an appropriate regulatory framework, mandatory before the wide-spread introduction of these technologies in the aerospace systems maintenance process, there has been a great interest and pull from the industry sector.

Keywords: Additive Manufacturing | Aeronautical maintenance | Augmented Reality | Industry 4.0

Abstract: Recently, the approach that defines the total life cycle assessment (LCA) and the end of life (EoL) in the early design phases is becoming even more promising. Literature evidences many advantages in terms of the saving of costs and time and in the fluent organization of the whole design process. Design for disassembly (DfD) offers the possibility of reducing the time and cost of disassembling a product and accounts for the reusing of parts and of the dismantling of parts, joints, and materials. The sequence of disassembly is the ordered way to extract parts from an assembly and is a focal item in DfD because it can deeply influence times and operations. In this paper, some disassembly sequences are evaluated, and among them, two methods for defining an optimal sequence are provided and tested on a case study of a mechanical assembly. A further sequence of disassembly is provided by the authors based on experience and personal knowledge. All three are analyzed by the disassembly order graph (DOG) approach and compared. The operations evaluated have been converted in time using time measurement units (TMUs). As result, the best sequence has been highlighted in order to define a structured and efficient disassembly.

Keywords: CAD | Disassembly | DOG | Sequence | TMU | Tools

Abstract: After the application of innovative design methodologies used to define an optimized technical specification, the present paper aims to manage the transition from conceptual design to construction project of an innovative means of urban transport, meeting the needs of 'Renewable energy’ requirements, which then decline into an hoverboard. Hoverboard can be considered, as described by Frizziero L. in “Conceptual design of an innovative electric transportation means with QFD, Benchmarking, TOP-FLOP Analysis” [1], Far East Journal of Electronics and Communications, a good solution for green mobility in urban traffic. The methodologies used in the precedent manuscripts were Quality Function Deployment (QFD), to identify quality requirements of the new green product, BENCH MARKING, to perform competition analysis, TOP-FLOP analysis in order to better improve the BENCH MARKING implementation, and finally TRIZ, for identifying the best way to generate innovation [1].

Keywords: Bench marking | Green energy & TRIZ & CAD | QFD | Renewable energy | Top-flop analysis

Abstract: Both economical and environmental aspects significantly influence the design process since the early phases of preliminary design. The total Life Cycle Assessment (LCA)and the End Of Life (EOL)of products have to be defined in the early design phase too. For industrial products that are not addressed to automatic manufacturing processes, the LCA and the EOL are an hard issue. However, the EOL of products, meant as recycling or reusing of parts, can be evaluated by means of the disassembly easiness of joints assembling the product, even when the production process is subject to an important contribute of workmanship. To facilitate this approach, a useful method is proposed in this paper to evaluate the disassembly of products, also of handcrafted products, in order to optimize the design process in the early preliminary phase. The method quantitatively evaluates an index, referred as the Disassembly Index, that describes the attitude of a product to be disassembled in order to recover its components (or its partial subassemblies). A case study is proposed to evaluate the disassembly attitude of structural subassemblies of a sailboat. The comparison to a standard product is proposed in order to test the sensitiveness of the Disassembly Index to automatic manufactured products. As conclusion, good performances to support the EOL evaluation of non conventional products have been demonstrated and a huge sensitiveness of the Disassembly Index to destructive and non destructive procedures is evidenced in the paper.

Keywords: Design for disassembly | Handcrafted product | Non-destructive disassembly & reusing of parts

Abstract: Today's market drives companies to change, adapt, and compete. Many consumers are increasingly looking at price, without sacrificing quality. In order to be attractive to the customer, companies must be able to offer the required quality at the lowest possible price. The life cycle of many products has been shortened compared to the past because now technologies are evolving faster. For these reasons, it is important that companies reevaluate all the operations that are carried out within them, to optimize them and eventually adopt new technologies if they offer interesting opportunities. In this discussion, we first study the design for disassembly, a technique that can bring several advantages during the life cycle of a component, offering the possibility of reducing time and cost of disassembling a product, and better reuse of the different materials of which it is composed. Subsequently, augmented reality is discussed, and how this technology is exploited in the world, especially in the industrial sector. During the work, we discuss a case study, with the gearbox being the object of analysis. This allows us to apply the theoretical concepts illustrated in a concrete way, allowing for a better understanding of the topics.

Keywords: Augmented reality | Computer aided design (CAD) | Design for disassembly | Gearbox

Abstract: Our purpose is to develop the preoperative diagnosis stage for orthopedic surgical treatments using additive manufacturing technology. Our methods involve fast implementations of an additive manufactured bone model, converted from CAT data, through appropriate software use. Then, additive manufacturing of the formed surfaces through special 3D-printers. With the structural model redesigned and printed in three dimensions, the surgeon is able to look at the printed bone and he can handle it because the model perfectly reproduces the real one upon which he will operate. We found that additive manufacturing models can precisely characterize the anatomical structures of fractures or lesions. The studied practice helps the surgeon to provide a complete preoperative valuation and a correct surgery, with minimized duration and risks. This structural model is also an effective device for communication between doctor and patient.

Keywords: 3D-printing | Additive manufacturing-modeling | CAT scan | Diagnosis | Orthopedics | Surgery

Abstract: In an increasingly competitive business world, the “time to market” of products has become a key factor for business success. There are different techniques that anticipate design mistakes and launch products on the market in less time. Among the most used methodologies in the design and definition of the requirements, quality function deployment (QFD) and design for Six Sigma (DFSS) can be used. In the prototyping phase, it is possible to address the emerging technology of additive manufacturing. Today, three-dimensional printing is already used as a rapid prototyping technique. However, the real challenge that industry is facing is the use of these machineries for large-scale production of parts, now possible with new HP multi-fusion. The aim of this article is to study the entire product development process taking advantage of the most modern models and technologies for the final realization of a case study that involves the design and prototyping of an innovative multifunctional fan (lamp, aroma diffuser and fan) through the Multi Jet Fusion of HP. To begin with, issues related to the DFSS, the QFD and their application to identify the fan requirements are explored. Once the requirements have been defined, the modern CAD design systems and the CAE systems for the validation of the case study will be analyzed and applied. Finally, HP’s Multi Jet Fusion methodology and design rules for additive manufacturing will be analyzed in detail, trying to exploit all the positive aspects it offers.

Keywords: CAD | CAE | Design for additive manufacturing | Design for six sigma | FEA | Multi jet fusion | Product development | QFD | Rapid prototyping

Abstract: In an increasing number of aggressive enterprise world, “time to market” concerning products has come to be a solution element because of enterprise success. There are exceptional techniques so expect layout mistakes or open products concerning the need between much less time. Among the most used methodologies in the design and setting about stability the requirements, Quality Function Deployment (QFD) and Design for Six Sigma (DFSS) execute remain used. In the prototyping phase, such is feasible in imitation of tackle the rising science regarding additive manufacturing. Today, three-dimensional stamping is in the meanwhile used as a rapid prototyping technique. However, the actual challenge that enterprise is going through is the use of these machineries for large-scale production about parts, at last viable along current HP Multi fusion. The aim of this article is to study the interactive design and engineering applied to the entire product development process taking advantage of the most modern models and technologies for the final realization of a case study that involves the design and prototyping of an innovative multifunctional fan (Lamp, Aroma Diffuser and fan) through the Multi Jet Fusion of HP. To begin with, issues related to the DFSS, the QFD and their application to identify the fan requirements are explored. Once the requirements have been defined, the modern CAD design systems and the CAE systems for the validation of the case study will be analyzed and applied. Finally, HP’s Multi Jet Fusion methodology and design rules for additive manufacturing will be analyzed in detail, trying to exploit all the positive aspects it offers.

Keywords: CAD | CAE | Design for additive manufacturing | Design for Six Sigma | FEA | Multi jet fusion | Product development | QFD | Rapid prototyping

Abstract: This paper presents the application of a low-cost 3D printing technology in pre-operative planning and intra-operative decision-making. Starting from Computed Tomography (CT) scans, we were able to reconstruct a 3D model of the area of interest with a very simple and rapid workflow, using open-source software and an entry level 3D printer. The use of High Temperature Poly-Lactic Acid (HTPLA) by ProtoPasta allowed fabricating sterilizable models, which could be used within the surgical field. We believe that our method is an appealing alternative to high-end commercial products, being superior for cost and speed of production. It could be advantageous especially for small and less affluent hospitals that could produce customized sterilizable tools with little investment and high versatility.

Keywords: 3D printing | Computed tomography | Diagnostic imaging | Mesh reconstruction | Rapid prototyping | Surgical planning

Abstract: Stylistic Design Engineering (SDE) is an engineered method developed for creating a structured way to realize Car Design Projects. SDE is composed by the following steps: (1) Stylistic Trends Analysis; (2) Sketches; (3) 2D CAD Drawings; (4) 3D CAD Models; (5) Rendering; (6) Solid Stylistic Model (defined also styling maquettes). In the present paper, SDE is applied to a new SUV, in particular to a new possibility of launching a new FIAT Campagnola, an off-roader that was very successful in the 1950s -1970s. This project deals with the exernal redesign of Fiat Campagnola. It has been carried out using various design technologies and methodologies that will be further explained in details, such as the Pininfarina method, the QFD (Quality Function Deployment) method, Benchmarking e Top Flop analysis. The work has been organized according to different phases. At first it has been studied the Fiat style, an essential step to understand better the features of the brand and also the main characteristics carried out during the decades. Later we carried on with the phase of the freehand sketches, being inspired by what was previously learned in every single step of study. This phase continued until a satisfactory form was found by analyzing and discarding the various proposals of the various types of style. Once the proposal was choosen, then the three-dimensional shape was obtained and on which it was possible to evaluate proportions and dimensions, also thanks to rendering software. All the analysis methodologies required for the quality of the project mentioned before have been used during all these phases.

Keywords: Benchmarking | Car design | Design engineering | QFD | Stylistic Design Engineering (SDE) | SUV

Abstract: The present work is a case study about the application of the methodology named Stylistic Design Engineering (SDE), that is an approach to develop car design projects in the industrial world. For attending this goal, it was chosen the E-segment car products, in particular following the necessity to fill a gap in the Alfa Romeo's market, which offers currently only models in A, B, SUV and coupe´ segments and needs a kind of model that could be successful in the market. In fact Alfa Romeo does not own a E-segment sport sedan flagship car model for years now (the last one was the 166). Based on this assumption and the fact that the largest car manufacturers are currently investing heavily on E segment cars, it was interesting to think about a new Alfa Romeo flagship model, maybe named with glorious name Alfetta. In the following pages will be illustrated the summary of the path that led to the final product following the instructions of SDE.

Keywords: Car design | Design engineering | Stylistic design engineering (SDE)

Abstract: Additive manufacturing (AM) is becoming an important alternative to traditional processes. AM technology shows several advantages in literature, and its use increases in aerospace, automotive and biomedicine. Time reduction in design-to-manufacturing cycle, customization, capability to generate complex shapes in one piece and ability to imitate low-weight bio-inspired shapes are the strength of designs based on AM. Due to its potentials, major progresses were done in AM, thanks to technology evolution and increased computational power. With regard to AM, voxelization can be defined as part's discretization in hexahedral elements, as done with pixels in 2D image. Voxels are used to speed-up geometry and algebraic manipulation thanks to their inherent advantages. This paper analyses advantages and criticalities of AM and voxel manipulation through a systematic literature review methodology. The analyses are based upon the filtering of a huge amount of publications available in literature up to obtaining the most significant 25 studies published in the last 5 years. The study's main result is the technology gap's identification, i.e. where AM and voxelization still need improvements, thus providing the reader with suggestions about possible further studies. Computer elaboration power and voxel discretization algorithms are suggested being key issues in AM's further development.

Keywords: Additive manufacturing | Design | Systematic literature review (SLR) | Voxel

Abstract: The primary purpose of this work is to organize, in the best possible way, the design of an ecological transport vehicle, using an advanced design methodology, namely design for six sigma (DFSS). The DFSS is indeed a design approach, able to implement, in a logical and integrated way, other advanced methodologies of systematic design, such as quality function deployment (QFD), TRIZ (in Russian, Teorija Rešenija Izobretatel'skich Zadač), benchmarking, top-flop analysis and others, in order to propose design solutions oriented both to quality and innovation, for satisfying customers. The above described has been demonstrated through the application of DFSS to a case study in which the set up phase of an industrial project was completed, without having overlooked any aspect useful for obtaining a new attractive product. The case study concerns the application of DFSS to a new low-polluting motorcycle. At the end of the work, the designer obtained the achievement of the conceptual project.

Keywords: Design For Six Sigma | Eco-motorbike | Project set up | QFD

Abstract: Both economic and environmental aspects significantly influence the design process since the early phases of preliminary design. The total Life Cycle Assessment (LCA) and the End of Life (EoL) of products have to be defined in the early design phases too but, for industrial products that are not feasible to automatic production, they are hard issues. However, the EoL of products can be assessed by evaluating the disassembly of joints assembling the product, even when the production process is subject to an important contribute of workmanship. In this paper, a useful method is proposed to analyze the disassembly plant of products, in order to optimize the design process in the early preliminary phases. The method quantitatively evaluates a Disassembly Index that describes the attitude of a product to be disassembled. A case study describes the disassembly attitude of structural subassemblies of a sailboat. In order to test the applicability of the model described to both manual and automated disassembly, a further application of the method is proposed on a Computer CPU. As result, the model demonstrated good sensitiveness to the testing of products quite different for dimensions, number of components, manufacturing processes and, in all cases, it quantified the disassembly easiness with good relevance.

Keywords: disassembly | handcraft | non-destructive | quantitative | reusing

Abstract: Considering the progressively expansive trade world, "time to market" of productions and goods has turned into a key element for business accomplishment. There are diverse practices that antedate design faults and unveil products on the market in minus time. Among the most used methods in the design and explanation of the necessities, quality function deployment (QFD) and design for Six Sigma (DFSS) can be used. In the prototyping stage, it is probable to address the emergent technology of additive manufacturing. Today, 3D printing is employed as a quick prototyping technique. Nevertheless, the tangible task which industry is fronting is the adoption of these machines for large-scale production of components, which is now possible with new HP multi fusion. The goal of this paper is to illustrate the entire product development process taking advantage of the most modern models and technologies for the final realization of a case study that involves the design and prototyping of an innovative multifunctional fan (lamp, aroma diffuser, and fan) through the multi jet fusion of HP. To begin with, issues related to the DFSS, the QFD and their application to identify the fan requirements are explored. Once the requirements have been defined, the modern CAD design systems and the CAE systems for the validation of the case study will be analyzed and applied. Finally, HP's multi jet fusion methodology and design rules for additive manufacturing will be analyzed in detail, trying to exploit all the positive aspects it offers.

Keywords: CAD | CAE | Design for additive manufacturing | Design for Six Sigma | FEA | Multi jet fusion | Product development | QFD | Rapid prototyping

Abstract: A numerical investigation is conducted in order to identify optimum trimming attitudes for resistance reduction in the application of high performance sailing yacht hulls. A lumped parameters model based on general unsteady equations of motion is developed and implemented in combination with a numerical scheme to conduct parametric studies and predict the overall performances of a specific sailing hull. Existing semi-empirical formulas for hydrodynamic coefficients are modified and applied in order to extend the speed range of application and obtain good agreement with available experimental data. Brief discussion of the numerical results is presented with emphasis on the possible applications in the field of modern sailing yachts.

Keywords: Hull | Lumped Parameters model | Performance | Planing occurrence | Resistance | Trim

Abstract: A new composite material, defined as Ductile High Energy Composite (DHEC), is analysed in this paper, with particular reference to the energy absorbed after high speed impacts and to the relevant failure mode. A set of DHEC and pure carbon fibre laminates presenting equal weight, equal bending strength or equal stiffness, respectively, have been compared measuring the energy absorbed after the impact of a bullet, through the difference between the total energy of the bullet and the one corresponding to its penetration in a wooden block after hitting the specimens. Fracture modes have been investigated using an optical microscope. Energy absorbed by DHEC laminates is of the same order than for pure carbon ones; however, the DHEC failure mode (referred to as “petaling”) presents a lower spreading of splinters respect to the pure carbon fibres (brittle fracture) case. Even though a wider testing campaign is necessary to better evaluate the DHEC properties, they appear to be suitable for adoption in all those applications where impacts can be harmful for end-users or people. Further research on high energy absorption properties is needed to better characterize these innovative composite materials, yet the outcome of this study suggests the high potential of DHEC.

Abstract: The present paper begins a series of features considered essential to the success of an innovative means of transport in the cities: the hoverboard. These features are obtained from a previous QFD analysis and are the starting point for a further TRIZ analysis that aims to obtain innovative technical solutions, in order to manage the transition from conceptual design to construction design. Through a hill model, the technical problems have been reformulated in terms of technical contradictions, and through the tools of TRIZ, as the matrix of contradictions, have come to obtain general resolution principles. From these general principles of resolution, innovative solutions for the construction of the innovative transport vehicle have been devised. These innovative solutions will be the starting point for a further engineering process that can be developed into further work.

Keywords: City transportation means | Contradictions | Hill model | Innovative solution | QFD | TRIZ

Abstract: Over the last years, good strategies for efficient manufacturing were considered increasing the volume of production and reducing the time and costs. Emerging design strategies as the Design for Environment and life cycle assessment, the Design for Sustainability, the Design for Disassembly moved the focus to conceive a product by taking care of all the effect that its use can cause to the economy, to the society and to the environment, also at its disposal. In this context, design strategies have to be enhanced in order to integrate innovation with sustainability and social care. Thus, the horizon for strategic manufacturing has to pay particular attention to the effects that it could produce to the surrounding environment. This way, some manufacturing techniques that could be considered obsolete in terms of sustainability awareness, but that are not yet ready to be replaced by advanced available technologies, need a requalification in order to be collocated in the current scenario. In this paper, the open moulding technique has been discussed in order to update the current manufacturing technique to meet the emerging sustainable strategies. Through the integration of QFD and TRIZ an innovative design method have been assessed to enhance the manufacturing process by means of computer aided engineering devices. PrinterCAD is a project that aims to manage additive and subtractive techniques, applied to complex and large-scale products, by means of an open source software with an integrated module, in order to enhance the CAD, CAM and slicing for the 3D printer’s languages intercommunication.

Keywords: CAD | CAM | Hybrid manufacturing | Open source | QFD | TRIZ

Abstract: The planning activity relative to physical items, environment, and services that adapts to optimize social, economic, and ecological impact is the target of sustainable design. Quality Function Deployment (QFD) achieves product design by choosing and defining factors that can be qualitatively argued. The aim of design is to match needs in new and innovative ways. In this perspective, the QFD aims to evaluate the quality of a design process. TRIZ is a design methodology that aims at defining and overcoming some critical issues that can affect the development of a product, by means of potential innovative solutions. In this paper, QFD and TRIZ analysis were adopted in order to validate a design method for direct open molds by means of a new strategy: hybrid manufacturing can reduce production time, use of material, and energy and waste consumption, employing subtractive and additive techniques efficiently combined.

Keywords: Additive | direct open mold | hybrid manufacturing | QFD | subtractive | TRIZ

Abstract: The paper discusses how Industry 4.0 could impact practitioners performing maintenance in aviation. The attention has been on Augmented Reality and Additive Manufacturing, which can support maintenance tasks and spare parts production respectively. Advantages and open issues are widely discussed and couple of case studies dealing with realistic scenarios are presented to support what has been proposed by the authors. The intention is to demonstrate that AR and AM are viable tools in aviation maintenance, even if effort is necessary to develop an appropriate regulatory framework, required before the introduction of these technologies in the maintenance process. Once applied to real maintenance tasks by airline companies, the practitioning community can develop best practices and the necessary regulation pertaining to maintenance and repair of aerospace systems using AR and AM technologies.

Keywords: Additive Manufacturing | Aeronautical Maintenance | Augmented Reality | Industry 4.0

Abstract: The aim of this article is to apply some design methodologies to define, as a first objective, an optimized technical specification and then, as a second objective, to manage the transition from conceptual design to construction project of an innovative means of urban transport, meeting the needs of 'renewable energy' requirements, which then decline into this new urban vehicle formed by a hoverboard and an electric scooter. The first part of the article is focused on the conceptual design of the means by using methodologies such as the Quality Function Deployment (QFD), applied in the first phase of the work to compare some of the most popular electric scooters on the market; we then used a typical method for product marketing, i.e., the decision-making process driven by the analysis of benchmarking, suitable for quantitatively organize competitive analysis and choosing innovation targets; finally, we implemented the top-flop analysis in order to better improve the benchmarking implementation, identifying the best product on the market, basing on the highest number of innovative requirements owned by it, as shown by Frizziero in 2018 and Meuli et al. in 1997. The second part of the article focuses on the project of the kick scooter through the use of a software for the FEA simulation and on the possible realization of the prototype through a suitable connecting component.

Keywords: Benchmarking | Conceptual design | Innovation | Product design | QFD | Top-flop analysis | Transport | Vehicle

Abstract: The aim of this work is to complete the QFD analysis carried out in a previous work that aimed to identify the main features that contribute to the success of a modern urban transport means: the hoverboard. Starting from this analysis, through the TRIZ methodology, resolutive principles have been identified for the realization of innovative solutions of the said urban transport means. In practice this analysis aims to manage the next phase of conceptual design realized with the QFD methodology and tries to guide the design process in its next phase. In this work was used the hill model, a characteristic model of the TRIZ methodology, and the technical innovative problems encountered were reformulated in terms of technical contradictions. Subsequently, general principles of inventive solutions were obtained using one of the tools of TRIZ: the matrix of contradiction. Finally, starting from these general principles of solution, innovative constructive solutions have been developed to be applied to the design of an innovative hoverboard.

Keywords: contradictions | hill model | innovative solution | QFD | TRIZ | urban transportation systems

Abstract: Opening from an examination of all the best features of accomplishment of the hoverboard, a modern vehicle for urban transport, we have created inventive ideas to design the transport means itself. Quality Function Deployment methodology has given us the requirements to start from, while the TRIZ methods have provided us the proposals and notions of an innovative landscape to which we tend. In practice, while the QFD methodology has a powerfully conceptual appeal, and it is the basis of our analysis, the TRIZ method gives a more innovative thrust and deals the aspects that are strongly constructive and concrete. The Matrix of Contradictions was used within the Hill Model, and through it, we have been able to rework the innovative problems, suggested by the QFD analysis, in terms of technical contradictions. At the end of the work, a number of suggestions were made to further innovate this urban and modern means of transport: the hoverboard.

Keywords: Contradictions | Innovative solution | QFD | TRIZ | Urban transportation systems

Abstract: Ternary hybrids including carbon, basalt and flax fibres in an epoxy matrix have been fabricated by hand lay-up, then consolidated by vacuum bagging using two different stacking sequences. Both configurations involved the use of carbon fibres on the outside, whilst basalt and flax fibres were disposed internally either in a sandwich or in an intercalated sequence. They were subjected to tensile, flexural and interlaminar shear strength test, then to falling weight impact with three different energies, 12.8, 25.6 and 38.4 J, studying damage morphology and impact hysteresis cycles. Intercalation of basalt with flax layers proved beneficial for flexural and interlaminar strength. As regards impact performance, the differences between the two laminates were quite limited: however, the presence of a compact core of flax fibre laminate or else its intercalation with basalt fibre layers had a predominant effect on impact damage features, with intercalation increasing their complexity.

Keywords: Flax | Hybrid | Impact behaviour | Mechanical properties

Abstract: This paper studies if adaptive grid refinement combined with finite-volume simulation of the incompressible RANS equations can be used to obtain grid-independent solutions of realistic flow problems. It is shown that grid adaptation based on metric tensors can generate series of meshes for grid convergence studies in a straightforward way. For a two-dimensional airfoil and the flow around a tanker ship, the grid convergence of the observed forces is sufficiently smooth for numerical uncertainty estimation. Grid refinement captures the details of the local flow in the wake, which is shown to be grid converged on reasonably-sized meshes. Thus, grid convergence studies using automatic refinement are suitable for high-Reynolds incompressible flows.

Keywords: Grid adaptation | Grid convergence | Hydrodynamic flows | Uncertainty estimation

Abstract: This paper describes the beneficial impact of an augmented reality based technique on the 3D printing process monitoring within additive manufacturing machines. A marker is applied in a fixed point of the rapid prototyping machine, integral with the component being manufactured; as an alternative, a markerless approach can be followed too. A virtual model of the object to be printed is superimposed to the real one. In this way, the shape of the object in different printing stages can be viewed. An interactive comparison between real and virtual model can be carried out both in manual and automatic mode. If manufacturing errors are detected, the building process can be stopped. Augmented reality technique allows an intuitive shape check of a part being printed with rapid prototyping technologies. In case of complex objects it helps the operator in the detection of possible errors along the manufacturing process; stopping the machine as soon as an error appears avoids waste of machining time and material. The average precision of the augmented reality is useful to find significant geometrical errors; geometrical deviations less than 1 mm can hardly be assessed both in manual and in automatic mode, and further studies should be carried out to increase the technique precision and range of application. To the best of the authors’ knowledge it is the first time where experiments on the integration between augmented reality and rapid prototyping to interactively monitor 3D parts’ printing have been investigated and reported in literature.

Keywords: 3D printing | Additive Manufacturing | Augmented Reality | Design | Rapid Prototyping

Abstract: The mounting attention to environmental issues requires adopting better disassembly procedures at the product's End of Life. Planning and reckoning different disassembly strategies in the early stage of the design process can improve the development of sustainable products with an easy dismissing and recycling oriented approach. Nowadays many Computer Aided Process Planning software packages provide optimized assembly or disassembly sequences, but they are mainly based on a time and cost compression approach, neglecting the human factor. The environment we developed is based upon the integration of a CAD, an Augmented Reality tool, a Leap Motion Controller device, see-through glasses and an algorithm for disassembly strategies evaluation: this approach guarantees a more effective interaction with the 3D real and virtual assembly than an approach relying only on a CAD based disassembly sequence planning. In such a way, the operator may not test in a more natural and intuitive way automatic disassembly sequences, but he/she can also propose different strategies to improve the ergonomics. The methodology has been tested in a real case study to evaluate the strength points and criticalities of this approach.

Keywords: Augmented Reality | CAD | Design for Disassembly | Disassembly Sequence Optimization

Abstract: Sustainable design aims at the creation of physical objects, environment and services that complies to optimize social, economic, and ecological impact. QFD is able to assess the product design by the choice and definition of parameters that can be qualitatively discussed. The purpose of design is to meet a need in new ways and in innovative ways. In this context, the QFD aims at evaluating the quality of a design process. TRIZ is a design method that aim at defining and overcome some critical issue that can affect the development of a product, by means of potential innovative solutions. In this paper QDF and TRIZ analysis have been adopted in order to validate a design method for direct open moulds, by a new strategy: hybrid manufacturing can reduce the production time, the use of material, the energy and the waste consumption, employing subtractive and addictive techniques efficiently combined.

Keywords: Additive | Direct open mould | Hybrid manufacturing | QFD | Subtractive | TRIZ

Abstract: We present the stress analysis of a pouring concrete device. In order to test the prototype of a pouring concrete equipment composed of fivearms with hollow rectangular cross sections, an extensive study about equipment for pouring concrete has been undertaken. An upgrade of a four-arms device already existing and actually working would be developed. Tests have been performed both on the prototype of the equipment and on a virtual model of the device, performed by a 3D CAD modeler and analyzed through FEM numerical programs. During experimental tests, a laser device has measured deflections at the end of the fifth arm, corresponding to applied loads. For measuring strains in the critical points highlighted by the numerical simulation strain rosette have been employed. In both the static and the dynamic conditions, Mohr's circles have been drawn from the 3D strain state and the 2D plane stress experimental records and they have been compared with those predicted through the finite element analysis. From the comparison between numerical and experimental results, a very good correlation has been obtained for static loading to assess the soundness of the virtual model.

Keywords: Articulated device | CAD | FEM | Mohr's circle | Strain analysis

Abstract: The study of the methodologies useful to support the assembly of parts is a challenging engineering task which can benefit of the most recent innovations in computer graphics and visualization technologies. This paper presents a proposal for an innovative methodology based on Virtual and Augmented Reality useful to support the components’ assembly. The herein introduced strategy is based upon a four stages procedure: at first the designer conceives the assembly sequence using a CAD system, visualizing the scene wearing an immersive Virtual Reality device. In the second stage, the same sequence is developed by an unexperienced user using the same equipment: the differences between two assembly sequences are recorded and exploited to detect critical points in the assembly sequence and to develop a Knowledge Based System. Finally, a virtual user manual is produced in Augmented Reality. When the final user uses the tool, the position of the object to assemble is detected by tracking the finger position of the user itself. A series of symbols and writings is added to the external scene to help the end-user in the assembly procedure. A test case based on the assembly of a scale model has been developed to evaluate the methodology. After an evaluation process, the procedure seems to be feasible and presents some advantages over the state-of-the-art methodologies proposed by literature.

Keywords: Assembly | Augmented Reality | Marker | Task automation | Virtual Reality

Abstract: This paper presents the development of a CAD conceived to support the modelling of lightweight and lattice structures just from the initial stages of the design process. A new environment, called LWSM (acronym of LightWeight Structures Modelling), has been implemented in Python programming language in an open-source CAD software to allow the fast modelling of several sandwich structures or the filling of solid parts with cubic and tetrahedral lattice structures which can be produced by Additive Manufacturing (AM) techniques. Several tests have been carried out to validate the tool, one of which is included in the paper. The design of a bracket component inside LWSM using a traditional dense geometry and a lattice structure is described. The use of Design for Additive Manufacturing (DfAM) functions helps the user in the design of innovative structures which can produced only with AM technologies. A significant change in the shape of the part respect to traditional solutions is noticed after the use of DfAM functions by experimenters: FEM analysis confirms a strong weight reduction.

Keywords: Additive manufacturing | CAD | FEM analysis | Lattice structure | Lightweight structures

Abstract: Sustainable design aims at the creation of physical objects, environment and services that complies to optimize social, economic, and ecological impact. QFD is able to assess the product design by the choice and definition of parameters that can be qualitatively discussed. The purpose of design is to meet a need in new ways and in innovative ways. In this context, the QFD aims at evaluating the quality of a design process. TRIZ is a design method that aim at defining and overcome some critical issue that can affect the development of a product, by means of potential innovative solutions. In this paper QDF and TRIZ analysis have been adopted in order to validate a design method for direct open moulds, by a new strategy: hybrid manufacturing can reduce the production time, the use of material, the energy and the waste consumption, employing subtractive and addictive techniques efficiently combined.

Keywords: Additive | Direct open mould | Hybrid manufacturing | QFD | Subtractive | TRIZ

Abstract: Hybrid Manufacturing (HM) is oriented to combine the advantages of additive manufacturing, such as few limits in shape reproduction, good customization of parts, distributive production, minimization of production costs and minimization of waste materials, with the advantages of subtractive manufacturing, in terms of finishing properties and accuracy of dimensional tolerances. In this context, our research group presents a design technique that aims to data processing that switches between additive and subtractive procedures, to the costs and time of product-manufacturing optimization. The component prototyping may be performed combining different stages (addiction, gross milling, fine milling, deposition…) with different parameters and head/nozzles and is able to work with different materials either in addictive, either in milling. The present paper is dedicated to introduce different strategies, or in other terms, different combinations of machining features (addictive or deductive) and different materials to complete a prototype model or mold. The optimization/analys ispiece of software is fully integrated in classic CAD/CAM environment for better supporting the design and engineering processes.

Keywords: CAD | CAM | Hybrid manufacturing | Multimaterial manufacturing | Process design

Abstract: Gamma radiation is a most efficient tool for sterilization, and especially effective on infesting pest, as it also kills the eggs. However, the large radiation doses entailed (tens of kilogray and up) might have adverse effects on desirable properties of wood. Of particular interest are the acoustic properties, as radiation would otherwise appear to be the perfect tool for the sterilization of musical instruments. The present investigation was aimed at determining the effects on acoustic and mechanical properties. Samples of four different wood species–poplar, oak, fir and maple–were prepared selecting wood completely free of visually detectable defects and subjected to incremental dose levels, reaching 25, 50, 100 and 200 kGy. A further set of samples were subjected to 200 kGy in one go, to investigate possible differences with incremental doses. Irradiation was conducted at an industrial irradiation facility, operating with a cobalt-60 source of the order of the megacurie. The mechanical tests were designed to measure the elastic modulus and the bending strength as well as force and displacement at rupture. Acoustic tests were developed specifically for this experiment, with the purpose of measuring the vibrational modes of the samples. All the samples exhibited discoloration and noticeable changes in properties: rigidity increased, load to rupture decreased, the material became more brittle and effects increased with increasing dose. The acoustic tests revealed a shift toward higher frequencies of all the vibrational modes, and this was exhibited for all wood species investigated. No meaningful difference was observed between the samples treated with incremental doses up to a total of 200 kGy and with a single 200 kGy dose.

Keywords: acoustic properties | Gamma ray sterilization | mechanical properties | wood

Abstract: Over the past decades, the technological development in the medical field, coupled with the ongoing scientific research, has led to the development and improvement of dental prostheses supported by screw-retained metal frameworks. A key point in the manufacture of the framework is the achievement of a passive fit, intended as the capability of an implant-supported reconstruction to transmit minimum strain to implant components as well as to the surrounding bone, when subject to any load. The fitting of four different kinds of screw-retained metal frameworks was tested in this article. They differ both in materials and manufacturing process: two frameworks are made by casting, one framework is made by computer-aided design and computer-aided manufacturing and one framework is made by electric resistance spot welding (WeldONE, DENTSPLY Implants Manufacturing GmbH, Mannheim, Germany). The passivity of the frameworks was evaluated on the entire system, composed of a resin master cast, the implant analogues embedded in the cast and the frameworks. Strains were recorded by means of an electrical strain gauge connected to a control unit for strain gauge measurements. The experimental tests were carried out in the laboratories of the Department of INdustrial engineering at the University of Bologna. The results of the test campaigns, which compared three samples for each technological process, showed that no significant differences exist between the four framework types. In particular, the frameworks made by the resistance welding approach led to a mechanical response that is well comparable to that of the other tested frameworks.

Keywords: Dental prosthesis | passive fit | screw-retained framework | strain gauge analysis

Abstract: Augmented Reality (AR) technology is becoming more available for everyday applications, providing advanced information about the observed objects. In this paper we present a system combining optical tracking and augmented reality with applications in local large areas. We use two different tracking technologies for positioning objects: the infrared marker-based motion capture system OptiTrack and the Vuforia software platform, which enables augmented reality app across the real world environment. We present a robust solution for communication between a client (mobile platform) and a server that computes all global tracking data. This technology has high potential for end users and can be of great benefit.

Keywords: Augmented reality | Client-server architecture | Mobile device | Network streaming | Tracking systems

Abstract: A novel Augmented Reality (AR) tool for structural health monitoring is illustrated in this work. It provides maintenance operators with the results of an impact detection methodology. It interacts with an eyepiece allowing the inspector to see the estimated impact position on the structure. Electric signals are collected by a network of piezosensors bonded on the structure to be monitored. Dispersive propagation compensation is performed to improve estimation robustness. Hyperbolic beamforming is exploited to locate the impact. Real-time impact data are finally fed to the AR eyepiece. The proposed approach is tested on a Cessna 150 engine cowling. Experimental results confirm the feasibility of the method and its exploitability in maintenance practice.

Keywords: Augmented reality | Guided waves | Structural health monitoring

Abstract: Traditional User/Maintenance Manuals provide useful information when dealing with simple machines. However, when dealing with complex systems of systems and highly miniaturized technologies, like UAVs, or with machines with millions of parts, a commercial aircraft is a case in point, new technologies taking advantage of Augmented Reality can rapidly and effectively support the maintenance operations. This paper presents a User/Maintenance Manual based on Augmented Reality to help the operator in the detection of parts and in the sequence to be followed to assemble/disassemble systems and subsystems. The proposed system includes a handheld device and/or an head mounted display or special goggles, to be used by on-site operators, with software management providing data fusion and overlaying traditional 2D user/maintenance manual information with an augmented reality software and appropriate interface. This device is connected by internet to a maintenance centre located in the aircraft manufacturer facilities. The on-site operator can directly access to multimedia content and historical information and can be helped or guided remotely by expert engineers residing at the manufacturer company offices. This resource may exploit Computer Aided Design and Product Data Management PDM remote facilities to prepare additional and specific 3D graphic content, supported also by a video and audio streaming from the camera and microphone of the on-site operator's handheld device. The proposed solution has revealed a number of significant advantages compared to the currently used operations: there is no need for preparing animations and graphic content for all the required maintenance sequences. The expert engineers and designers can both be involved directly in the maintenance tasks, a useful mean of feedback to evaluate the design for further projects or for project improvement. Additionally, the sensitive data is not shared outside the company since data is transmitted for visual display but it is stored on a secured location.

Abstract: In this paper, a comparison between the mechanical characteristics of two different natural fiber composites has been carried out. The two composites were made using two different environmentally friendly resins, but with the same flax fiber reinforcement. Thirty-two specimens were tested for tension, bending and shear. The results obtained in the tensile and bending tests are acceptable according to the Standards, whereas those of the shear tests were discarded, since the samples exhibited unacceptable failure modes. In light of the results obtained, both in terms of strength and stiffness, the isophthalic resin (181EN2X) outperformed the vinyl ester resin (VEef220ST). In the case of the isophthalic resin, microscopic observations showed a good adhesion between the matrix and the fiber, with a small amount of air inclusions. The present study demonstrates that the mechanical characteristics of flax reinforced and environmentally friendly resins are similar to those achievable with the same fibers using conventional resins.

Keywords: Environmentally friendly resin | Flax | Mechanical properties | Natural fibre composites

Abstract: Class-A curves show very appreciable features in terms of smoothness and curvature trend that is commonly perceived as high quality profiles. These curves are commonly sketched by experienced operators, but at the present day no tools are available to transform a B-spline into a Class-A curve. The k-neigh-fast is an improved version of k-neighbours algorithm, described in Amati et al. (Comput Graph 30(3):345-352, 2006), aiming to transform a B-spline non-Class-A slope into a B-spline Class-A curve by manipulating a group of k geometric coefficients. Once the level of detail (LOD) representation of a curve has been computed, the k-neigh-fast algorithm, detects those control points representing non-Class-A imperfections. At each LOD, the algorithm individuates the detail coefficient maximizing the internal functional. Then k-neighbours has been modified applying filtering criteria. A control step starts to verify the transformation from a non-Class-A curve into a Class-A shape. This process is repeated until the chosen stopping condition is satisfied. The final shape with improved smoothness and monotonic curvature is achieved through manual procedure. This paper reports results dealing on an improved and faster wavelet-based LOD filtering implementation used to generate very smooth set of profiles that own to Class-A set. The LODs representation allows to divide curves into their coarser least-square approximations and details coefficients. The extraction and manipulation of details with multi-level filtering, allows to determine geometric imperfections. This method has been tested to the smoothing of the hull profile of ships: results are good since the non-A-curve are well converted in smoother lines. A more efficient implementation, based on a flexible LOD representation led to prove many benefits of this techniques; the tests performed exploiting a computer program implementation have demonstrated very good results in most of simulations considered. © 2012 Springer-Verlag France.

Keywords: CAD | Class-A curves | Design | Smoothing optimization | Wavelets

Abstract: This paper illustrates a Human-Machine Interface based on Augmented Reality (AR) conceived to provide to maintenance operators the results of an impact detection methodology. In particular, the implemented tool dynamically interacts with a head portable visualization device allowing the inspector to see the estimated impact position on the structure. The impact detection methodology combines the signals collected by a network of piezosensors bonded on the structure to be monitored. Then a signal processing algorithm is applied to compensate for dispersion the acquired guided waves. The compensated waveforms yield to a robust estimation of guided waves difference in distance of propagation (DDOP), used to feed hyperbolic algorithms for impact location determination. The output of the impact methodology is passed to an AR visualization technology that is meant to support the inspector during the on-field inspection/diagnosis as well as the maintenance operations. The inspector, in fact, can see interactively in real time the impact data directly on the surface of the structure. Here the proposed approach is tested on the engine cowling of a Cessna 150 general aviation airplane. Preliminary results confirm the feasibility of the method and its exploitability in maintenance practice. © 2014 SPIE.

Keywords: Aircraft Maintenance | Augmented Reality | Guided waves | Impact localization | Nondestructive Testing | Warped Frequency Transform

Abstract: This paper proposes an augmented reality (AR) strategy in which a Lamb waves based impact detection methodology dynamically interacts with a head portable visualization device allowing the inspector to see the estimated impact position (with its uncertainty) and impact energy directly on the plate-like structure. The impact detection methodology uses a network of piezosensors bonded on the structure to be monitored and a signal processing algorithm (the Warped Frequency Transform) able to compensate for dispersion the acquired waveforms. The compensated waveforms yield to a robust estimation of Lamb waves difference in distance of propagation (DDOP), used to feed hyperbolic algorithms for impact location determination, and allow an estimation of the uncertainty of the impact positioning as well as of the impact energy. The outputs of the impact methodology are passed to a visualization technology that yielding their representation in Augmented Reality (AR) is meant to support the inspector during the on-field inspection/diagnosis as well as the maintenance operations. The inspector, in fact, can see interactively in real time the impact data directly on the surface of the structure. To validate the proposed approach, tests on an aluminum plate are presented. Results confirm the feasibility of the method and its exploitability in maintenance practice. © 2013 Luca De Marchi et al.

Abstract: This paper describes the design and development of a virtual environment conceived to support flight operations of an Unmanned Air Vehicle (UAV) used for wind mapping in the proximity of existing or planned wind farms. The virtual environment can be used in pre-flight briefings aiming to define a trajectory from a list of waypoints, to change and eventually re-plan the mission in case of intersection with no fly zones, to simulate the mission, and to preview images/videos taken from the UAV on-board cameras. During flight, the tool can be used to compute the wind speed along the trajectory by analyzing the data streaming from the UAV. The integration of Augmented Reality (AR) techniques in the flight environment provides assistance in remotely piloted landings, and allows visualizing flight and environmental information that are critical to the mission. For example, when spatial and temporal knowledge of the wind speed is required, AR can be used to overlap wind speed vectors to the external real environment. Eventually, wind vectors and UAV position and attitude can be visualized in a Virtual Reality systems based on Cave Automatic Virtual Environments (CAVE) or stereoscopic view. Tests shows that the proposed tool and methodology can effectively support wind speed detection missions since it can improve operational safety and contribute to the accomplishment of mission goals. Copyright © 2013 SAE International.

Abstract: This paper describes the development of an innovative hardware and software tool useful to sketch planar shapes in computer aided industrial design and computer aided design systems. The proposed system is based upon a tracked touch screen hand-held by the designer. The whole system is composed by a portable hand-held small touch screen (tablet size), a fixed LCD display and an optical tracking equipment. The touch screen is added by a simple camera for mixed reality optional functionality and its 6° of freedom movements are tracked. A custom software has been implemented for optimal exploitation and 3D sketching. The system acts as a free sketching device, a 3D mouse, as a realtime virtual and physical sketching plane or an external shape remodelling tool. The results obtained confirm the benefits of the virtual tablet in design, modelling and reverse engineering of industrial products. Copyright © 2013 Inderscience Enterprises Ltd.

Keywords: Computer aided sketching | Pose estimation | Reverse engineering | Sensor fusion | Touch screen tablet

Abstract: The Generalized Differential Quadrature (GDQ) method is applied to study the dynamic behavior of anisotropic doubly-curved shells and panels of revolution with a free-form meridian. The First-order Shear Deformation Theory (FSDT) is used to analyze the above mentioned moderately thick structural elements. In order to include the effect of the initial curvature in the evaluation of the stress resultants three different approaches, specifically Qatu approach, Toorani-Lakis approach and Reissner-Mindlin approach, are considered and compared. An improvement of the Classical Reissner-Mindlin Theory (CRMT) using a different kinematical model is considered. By so doing a generalization of the theory of anisotropic doubly-curved shells and panels of revolution is proposed. Four different anisotropic shell theories, namely General First-order Shear Deformation Theory by Qatu (GFSDTQ), General First-order Shear Deformation Theory by Toorani-Lakis (GFSDTTL), General First-order Shear Deformation Theory by Reissner-Mindlin (GFSDTRM) and Classical Reissner-Mindlin Theory (CRMT), are compared in order to show the differences and the accuracy of these theories. The solution is given in terms of generalized displacement components of points lying on the middle surface of the shell. Simple Rational Bézier curves are used to define the meridian curve of the revolution structures. Results are obtained taking the meridian and circumferential coordinates into account, without using the Fourier modal expansion methodology. Furthermore, GDQ results are compared with those obtained by using commercial programs such as Abaqus, Ansys, Nastran, Straus and Pro/Mechanica. Very good agreement is observed.

Abstract: The Generalized Differential Quadrature (GDQ) Method is applied to study laminated composite shells and panels of revolution. The mechanical model is based on the so called First-order Shear Deformation Theory (FSDT) deduced from the three-dimensional theory, in order to analyze the above moderately thick structural elements. In order to include the effect of the initial curvature from the beginning of the theory formulation a generalization of the kinematical model is adopted for the Reissner-Mindlin theory. The solution is given in terms of generalized displacement components of points lying on the middle surface of the shell. The results are obtained taking the two co-ordinates into account, without using the Fourier expansion methodology, as done in semi-analytical methods. After the solution of the fundamental system of equations in terms of displacements and rotations, the generalized strains and stress resultants can be evaluated by applying the Differential Quadrature rule to the generalized displacements themselves. The transverse shear and normal stress profiles through the laminate thickness are reconstructed a posteriori by simply using local three-dimensional equilibrium equations. No preliminary recovery or regularization procedure on the extensional and flexural strain fields is needed when the Differential Quadrature technique is used. By using GDQ procedure through the thickness, the reconstruction procedure needs only to be corrected to properly account for the boundary equilibrium conditions. In order to verify the accuracy of the present method, GDQ results are compared with the ones obtained with 3D finite element methods. Stresses of several composite shell panels are evaluated. Very good agreement is observed without using mixed formulations and higher order kinematical models. Various examples of stress profiles for different shell elements are presented to illustrate the validity and the accuracy of GDQ method. © 2012 Elsevier Ltd. All rights reserved.

Keywords: First-Order Shear Deformation Theory | Generalized Differential Quadrature method | Laminated composite shells | Shear and normal stress recovery

Abstract: The Generalized Differential Quadrature (GDQ) Method is applied to study laminated composite degenerate shell panels such as rectangular and annular plates. The theoretical treatment is maintained general in order to expose in a unique way the procedure adopted to obtain the stress profiles through the thickness of plates without specifying the equations for rectangular and annular plates. By simply imposing some geometrical relations the equations governing the problem of plates under consideration, that are degenerate shells, are inferred from the theory of shells of revolution. The mechanical model is based on the so called First-order Shear Deformation Theory (FSDT) deduced from the three-dimensional theory in order to analyse the above moderately thick structural elements. The solution is given in terms of generalized displacement components of points lying on the middle surface of the plate. After the solution of the fundamental system of equations in terms of displacements and rotations, the generalized strains and stress resultants are evaluated by applying the Differential Quadrature rule to the generalized displacements. The transverse shear and normal stress profiles through the laminate thickness are reconstructed a posteriori by using local three-dimensional elasticity equilibrium equations. No preliminary recovery or regularization procedure on the extensional and flexural strain fields is needed when the Differential Quadrature technique is used. By using GDQ procedure through the thickness, the reconstruction procedure needs only to be corrected to properly account for the boundary equilibrium conditions. In order to verify the accuracy of the present method, GDQ results are compared with the ones obtained with semi-analytical formulations and with 3D finite element methods. Stresses of several composite plates are evaluated. Very good agreement is observed without using mixed formulations and higher order kinematical models. Various examples of stress profiles for rectangular and annular plate elements are presented to illustrate the validity and the accuracy of GDQ method. © 2012 Elsevier Ltd. All rights reserved.

Keywords: Laminates | Numerical analysis | Plates | Shear and normal stress recovery

Abstract: In this paper, the generalized differential quadrature (GDQ) method is applied to study the dynamic behavior of functionally graded materials (FGMs) and laminated doubly curved shells and panels of revolution with a free-form meridian. The First-order Shear Deformation Theory (FSDT) is used to analyze the above mentioned moderately thick structural elements. In order to include the effect of the initial curvature a generalization of the ReissnerMindlin theory, proposed by Toorani and Lakis, is adopted. The governing equations of motion, written in terms of stress resultants, are expressed as functions of five kinematic parameters, by using the constitutive and kinematic relationships. The solution is given in terms of generalized displacement components of points lying on the middle surface of the shell. Simple Rational Bézier curves are used to define the meridian curve of the revolution structures. Firstly, the differential quadrature (DQ) rule is introduced to determine the geometric parameters of the structures with a free-form meridian. Secondly, the discretization of the system by means of the GDQ technique leads to a standard linear eigenvalue problem, where two independent variables are involved. Results are obtained taking the meridional and circumferential co-ordinates into account, without using the Fourier modal expansion methodology. Comparisons between the ReissnerMindlin and the TooraniLakis theory are presented. Furthermore, GDQ results are compared with those obtained by using commercial programs such as Abaqus, Ansys, Nastran, Straus and Pro/Mechanica. Very good agreement is observed. Finally, different lamination schemes are considered to expand the combination of the two functionally graded four-parameter power-law distributions adopted. The treatment is developed within the theory of linear elasticity, when materials are assumed to be isotropic and inhomogeneous through the lamina thickness direction. A two-constituent functionally graded lamina consists of ceramic and metal those are graded through the lamina thickness. A parametric study is performed to illustrate the influence of the parameters on the mechanical behavior of shell and panel structures considered. © 2011 Elsevier Ltd. All rights reserved.

Keywords: Doubly curved shells of revolution | Free vibrations | Functionally graded materials | Generalized differential quadrature method | Laminated composite shells | Rational Bézier curves

Abstract: This paper describes the development of an innovative harware and software tool useful to sketch planar shapes in Computer-aided Industrial Design and Computer Aided Design systems. The whole system is composed by a portable hand-held small touch-screen, a large fixed main screen and an optical tracking equipment. The touch-screen is added by a simple camera for Mixed Reality optional functionality and its 6 degrees of freedom movements are tracked through four groups of Light Emitting Diodes located on back of the monitor. A Nintendo® WiiMote with infrared camera is used to acquire Light Emitting Diodes relative positions for real-time tracking. A 6 degrees of freedom Inertial Measurement Unit has been added to improve the stability of the pose estimation: an Extended Kalman Filter provides the data fusion. Furthermore, a custom software has been implemented for optimal exploitation of a such configured hardware and facilitate input and 3D sketching. The physical tablet can be used in three different ways: as a 3D mouse which sets the point of view of the main screen according to its attitude, to set a plane in the main screen so that a 2D sketch can be referenced in the 3D space and as a support device to improve the manual draw of an object by overwriting the image contour. The results obtained confirms the usefulness of the virtual tablet in design, modelling, and reverse engineering of industrial products. © Organizing Committee of TMCE 2010 Symposium.

Keywords: Computer aided sketching | Pose estimation | Reverse engineering | Sensor fusion | Virtual tablet

Abstract: A new method of reverse engineering for fast, simple and interactive acquisition and reconstruction of a virtual three-dimensional (3D) model is presented. We propose an active stereo acquisition system, which makes use of two infrared cameras and a wireless active-pen device, supported by a reconstruction method based on subdivision surfaces. In the 3D interactive hand sketching process the user draws and refines the 3D style-curves, which characterize the shape to be constructed, by simply dragging the active-pen device; then the system automatically produces a low-resolution mesh that is naturally refined through subdivision surfaces. Several examples demonstrate the ability of the proposed advanced design methodology to produce complex 3D geometric models by the interactive and iterative process that provides the user with a real-time visual feedback on the ongoing work. © 2010 Elsevier Ltd. All rights reserved.

Keywords: Computer-aided design | Interactive 3D input device | Subdivision surfaces

Abstract: A fast and interactive implementation for camera pose registration and 3D point reconstruction over a physical surface is described in this paper. The method (called SRE-Smart Reverse Engineering) extracts from a continuous image streaming, provided by a single camera moving around a real object, a point cloud and the camera's spatial trajectory. The whole per frame procedure follows three steps: camera calibration, camera registration, bundle adjustment and 3D point calculation. Camera calibration task was performed using a traditional approach based on 2-D structured pattern, while the Optical Flow approach and the Lucas-Kanade algorithm was adopted for feature detection and tracking. Camera registration problem was then solved thanks to the Essential Matrix definition. Finally a fast Bundle Adjustment was performed through the Levenberg-Marquardt algorithm to achieve the best trade-off between 3D structure and camera variations. Exploiting a PC and a commercial webcam, an experimental validation was done in order to verify precision in 3D data reconstruction and speed. Practical tests helped also to tune up several optimization parameters used to improve efficiency of most CPU time consuming algorithms, like Optical Flow and Bundle Adjustment. The method showed robust results in 3D reconstruction and very good performance in real-time applications. © 2010 Springer-Verlag.

Keywords: 3D vision | Interactive modeling | Reverse engineering | Shape reconstruction | Surface remodeling

Abstract: This paper reports the results of a PDM and CAD plug-in implementation for semi-automatic and real-time similar component search in mechanical field. The approach exploits a string based component description similar to the well-known methodology, called Group Technology (GT), in order to check interactively feature similarity over a PDM database. The GT code contains component geometric data and manufacturing information. The software developed is suitable for encoding 2D and 3D parts. A guided GUI returning the GT code has been implemented for 2D drafts. For 3D parts, instead, the encoding procedure is completely integrated in the modelling CAD interface and the code is calculated incrementally feature by feature. So the part similarity assessment is interactive: the designer may visualize similar parts stored in the PDM and decide whether changing singular feature or using a retrieved (similar) part. Several case studies described in the paper demonstrate GUI usage, search algorithm and results. With PDM correctly configured, results are very good since the GT coding, the part retrieval and the quoting are really interactive. © 2010 CAD Solutions, LLC.

Keywords: Cost prediction | GT code | Interactivity | Similarity assessment

Abstract: A real-time and robust algorithm for 3D camera registration in a Mixed Reality (MR) environment is described in this paper. The most used technique for camera pose (position and orientation with respect to a fixed or moving object) is based on fiducial marker tracking. This method guarantees good results in real-time with a single camera, but needs several high contrast printed markers on external world in order to make possible the calculation of camera parameters and positioning. Thus real 3D geometric data are grabbed only through already known markers. The aim of this research is a real-time monocular camera tracking and registration through automatic image features extraction from video streaming. The first implementation of the method, several examples and confrontation with non interactive algorithm for SFM (Structure From Motion) have demonstrated that this meets the real-time response and sufficient precision needed by a Mixed Reality environment. © The Eurographics Association 2007.

Abstract: Although the 3D shape recovery of a real object have been greatly improved in the last few years, modeling a complex virtual object by starting from the real prototype is still a very time-consuming activity. In this paper an originally conceived method and testing software to recover a CAD model from a real object is presented. The developed software tool joins a professional Computer-Aided Design (CAD) and a Mixed Reality (MR) tool in the same interface, enabling the operator to use standard CAD tools and features together with a camera, which provides external image streaming displayed in the workspace background. Moreover, a special programmed library performs a real-time calculation of camera position and other parameters with respect to standard markers in order to drive the CAD 3D virtual camera and align it to external world. In that way rendered virtual models may be superimposed to external images of reality grabbed by the video camera. Thus with MR-CAD tool the operator may easily recover a complex shape directly from the external views of a real object or may start the object re-design from the previous reconstructed geometry. Furthermore the interface is totally integrated in a CAD environment, both avoiding to work with unfamiliar new software and exploiting CAD geometry database and tools. Finally, MR-CAD can be considered a significant step ahead in the bi-directional interaction of virtual and real models, reducing also the gap between real prototypes and CAD data.

Keywords: Augmented reality | Mixed-reality | Reverse engineering | Virtual prototyping

Abstract: This paper reports the work on a novel wavelet-based multi-scale filtering application used to generate very smooth subset of profiles known as Class-A curves. The multi-scale representation, based on B-spline wavelets, allows to split a spline curves in terms of a coarser least-square approximation and details coefficients. It raises that non-Class-A curves are determined by geometric imperfections strongly connected to the details coefficients. The extraction and manipulation of details with multi-scale filtering allows to select and evaluate geometric imperfections. Finally, an efficient algorithm devoted to improve a given non-Class-A profile to a Class-A curve has been implemented and tested with several examples in order to check and visualize the results. © 2006 Elsevier Ltd. All rights reserved.

Keywords: Class-A curve | Curvature distribution | Multi-resolution | Smooth curves | Wavelets

Abstract: The aim of this work is an efficient methodology development for a real-time control of human assembling sequences of mechanical components. The method involves a CAD environment, an hardware system, referred to as a PAA (Personal Active Assistant), and a set of Mixed Reality features. The whole scheme is targeted to positively influence the connection between CAD and Mixed Reality in order to proficiently reduce the gap between engineers and manual operators. The system is based on a CAD assembly module and on an Mixed Reality wearable equipment. It can be used to improve several activities in the industrial field, such as operator professional training, optimal assembly sequence seeking or on-field teleconferencing (suitable for remote collaboration or for full exploitation of Concurrent Engineering suggestions during design and set up stages). The main characteristic of PAA is a real-time wireless linkage to a remote server or designer workstation, where project geometric database is stored. The Mixed Reality wearable equipment consists of an optical see-through display device and a PAA head-mounted camera. The user can freely operate in the mixed environment, while the camera can record the human driven assembly sequence and check the efficiency and correctness via object recognition: an incrementally sub-assembly detection algorithm has been developed in order to achieve complex dataset monitoring. Conversely, designer or assembly planner can exploit the peculiarities of Mixed Reality-based assembly: a straightforward interaction with the assembly operator can be obtained by sending vocal advices or by displaying superimposed visual information on the real scene. In the paper a new method for CAD models and Mixed Reality environment integration will be presented and discussed in order to improve and simplify personnel training or warehouse part seeking. © 2006 - IOS Press and the auther(s). All rights reserved.

Keywords: Assembly | CAD | Concurrent engineering | Mixed reality

Abstract: This work is devoted to introduce a new Bi-manual system that provides an handful user interface for free-form surface modeling. The Bi-Manual user interface (Bi-Manual-UI) has been realized exploiting a 6DOF (degree-of-freedom) motion controller. The system considers the integration of a motion controller with a pen based graphical tablet. The Bi-Manual-UI aims to increase the interaction with users enhancing the creation of complex shapes. A sketching plane is available to users who can control its 3D position by the motion controller. In the meanwhile, users can draw a section curve on the plane, using the pen tablet. Moving the plane into a 3D space, the set of created curves area used to generate interactively the free-form surface. Unlikely standard CAD systems, the developed framework enables to change the sectional curve in real-time leading to the creation of shapes with different sections. Advantages introduced by this innovative instrument consist in the usage of it as a true geometric modelling tool and not only in order to move and rotate virtual camera.

Keywords: 6DOF (degree of freedom) | Bi-manual interaction | Computer-aided design | Free-form surface modelling | User interface

Abstract: The use of 3D tracking systems in a Virtual Reality environment may definitely change CAD interfaces and free-form surface modelling. In this paper an original method for full 3D interactive surface shaping and modifying is described. VISM (Virtual Integrated Surface Modeller) has been developed with the leading idea that 3D tracking system can dramatically speed up modelling sessions. On the opposite of a W-I-M-P (Windows-Icons-Menu-Pointer), paradigm common to most current CAD systems, VISM demonstrates that Virtual Reality devices can manage all types of surface in a unique shape generative action. Unlike "Virtual Clay" based and "Metaball" modelling techniques, VISM both wants to give to engineers and designers a more intuitive and natural tool to get 3D shapes. Based on Polhemus Fastrak and stereoscopic vision, VISM doesn't provide icons to (he designer, leading to a "null icons" and "null menu" full 3D interface. The new interface is fully implemented on bi-manual input system on top of a Virtual Reality environment. The entity grabbing is also supported by pinch-enabled gloves. The designer exploits a NURBS curve tool to deform a NURBS surface and extracts drive curve direction from his right hand movement. The curve tool may be also real-time deformed with left hand through node-control point repositioning. Furthermore the modeller is fully implemented using NURBS curves and surfaces and a fast surface-over-curve positioning and deformation has been implemented, replacing both traditional snapping and picking activities.

Keywords: 3D interface | CAD | Spatial Tracking | Surface modelling | Virtual Reality

Abstract: The reuse of free-form surface features (FFF), created in different design sessions, is a growing research field in geometric modelling. The development of this research field will give important improvements in surface shape activities in modern CAD and CAID (Computer-aided Industrial Design) systems. Traditionally, the surface modelling software has been founded on parametric definition of curves and surfaces (Splines and NURBS), giving to designers a great flexibility and power, but lacking in global shaping tools. Nowadays, the most exploited modelling commands are curve-constraining rules and control points repositioning: the first is very time-consuming, while the second is not global and may lead to a smooth-less surfaces. In this paper, we investigate on an application of Multiresolution Analysis (MRA) theory in wavelets representation, to develop a innovative global shaping tool for free-form features reusing. The developed algorithm aims to overcome the traditional control points description thanks to a wavelets coefficients representation of geometry features. The final result of this approach is to give the possibility in building a designer's own features library, which can be available in different modelling sessions, both improving surface quality and reducing time-consuming shaping procedures in product design development.

Keywords: Free-form features reuse | LOD | Multiresolution | Wavelets

Abstract: In this paper we introduce a virtual integrated surface modeller (VISM) equipped with two advanced tools for 3D surface modelling in virtual reality (VR). VISM has been implemented thinking that the immediate visual feedback greatly improve complex surface modelling and also creativity. The proposed new tools are progressive skinning (PS) and curve-over-surface shaping (COSS), both implemented on a bimanual virtual environment. PS lets the designer generate a new surface by interactively and automatically adding section curves to a non-uniform rational B-spline surface. COSS is based on curve-over-a-surface progressive constraining in order to deform an area of an existent surface. Efficient numerical solutions are proposed to achieve true interactive modelling sessions.

Keywords: 3d geometric modelling | Human-machine interaction | Non-uniform rational B-spline | Real-time interaction | Virtual reality

Abstract: An integrated environment based on CAD assembly software and on an Augmented Reality wearable system is used to improve the overall integration between engineering design and real prototypes manufacturing. The environment following called - Personal Active Assistant (PAA) - exploits a CAD tool connection to remarkably improve object recognition, best assembly sequence optimization, and operator instructions generation. PAA is real-time and wirelessly linked to a remote server or designer workstation where project geometric database is stored. The PAA head-mounted camera is also able to acquire the human-driven assembly sequence and check the efficiency and correctness via object recognition: an incremental sub-assembly detection algorithm has been developed in order to achieve complex dataset monitoring. On the other hand, the Augmented Reality-based assembly evaluation tool allows engineers to interact directly with the assembly operator while manipulating the real and virtual prototype components. Information from the assembly planner can be displayed, directly superimposed, on the real scene by using a see-through head-mounted display. Thus the new combined software and hardware equipment may be considered a step ahead in the support of true concurrent engineering and remote collaboration, strongly improving this latter through a better heterogeneous task integration. Several tests have been performed also to achieve personnel training and warehouse part seeking.

Keywords: Assembly | Augmented reality | CAD | Concurrent engineering | Virtual reality

Abstract: A prst step towards a semi-immersive Virtual Reality (L!R) interface for Finite Element Analysis (FEA) is presented in this paper. During recent years, user interfaces of FM solvers have matured from characterbased command-line driven implementations into easy-touse graphical user interfaces (GUS). This new generation of GUIs provides access to intuitive and productive tools for the management and analysis of structural problems. Many pre-And post-processors have been implemented targeting the simplification of the manmachine interface in order to increase the ease of use and provide better visual analysis of FEA solver results. Nevertheless, none of these packages provides a real 3Denabled interface. The main objective of this project is to join state-of-The-Art visualization technology, VT devices, and FM solvers into the integrated development environment VRFM.

Keywords: 3D Modeling | Finite Element Analysis | Interactive Modeling | Simulation. | Virtual Reality