Product design and engineering

As experience in EcoDesign increases, academic and industry thinking is moving towards the more advanced stages of EcoDesign; moving away from product improvement and product redesign into the more holistic approaches of Alternative Function Fulfilment (AFF) and system innovation. This paper investigates how modularity concept, applied to product design, allow much degrees of freedom for the designer, more possibility to reduce environmental impact related to product life-cycle and increase the interaction between LCA and the earlier stages of the (Eco)design process. A method, based on the product modularity concept, to increase LCA usability for the designers is proposed in this paper.

Keywords: Alternative Function Fulfilment , Ecodesign , LCA , Modularity

Designing a new product, in most cases, means a modification of an existing one. Both adopting known solutions in different products, that inserting new technological processes into a consolidated context, the most design effort must be dedicated to the early evaluation of the impact of needed engineering changes to achieve the final result, in terms of cost, quality and time. Such activity is particularly strategic in the modular product development. The aim of our research work is to develop a method and the related tools that enable designers to easily represent the product platform, to structure the relations between modules defined at different levels of detail and, hence, to simulate, analyze and evaluate the modifications impact during the new product variant definition phase. A multi-level product structure able to represent the product informative content at different levels of detail is presented.

Keywords: Change propagation , Conceptual design , Modularity

During the development of complex industrial products, several physical and engineering domains are involved. Mechatronic products, for example, are the result of the synergy among mechanical engineering, electronics and computer science. Therefore, the development of such products requires a constant and continuous cooperation among the designers responsible of the different fields of knowledge. Further, to prevent possible design errors before the building of the physical mock-up, there is the need of a simulation environment able to perform analyses in several physical domains. A possible solution to this need is the employment of a software package able to compute multi-domain simulations. However, the existent solutions do not allow engineers to employ their own solver or to choose the best combination among the available simulation software. This paper describes the development of an experimental middleware that supports the communication among different synchronously running simulations, solving interrelated problems and integrating a graphical interactive environment to support the interdisciplinary team in the design review and decision taking.

The design methodologies traditionally employed to develop mechatronic products are articulated in a sequence of phases: mechanical design, choice of actuators, sensors and other devices, design of the control system. Traditional methodologies usually end with the realisation of the physical prototypes used to perform the tests that are needed to optimise the product, and to verify the effectiveness of the design solutions adopted in the previous phases. The realisation of the physical prototypes is, usually, a complex and expensive task in which design errors and non-optimal solutions, related to the design phase, cause lateness in product launch and development costs increase. The present paper describes a design methodology devoted to the development of mechatronic products supported by an integrated and interactive co-simulation. This methodology, in fact, allows designers from different domains (mechanical, electronic and software engineers) to follow a classic top-down approach in which, starting from the conceptual phase, they can check, at each milestone of the project, the functionality of the product at different stages and for different levels of detail. At the end of the design process the engineers can directly interact with the mechatronic model by using the product interface implemented in the control system. The actions of the user are processed by the electronics simulation software that dialogues with actuators, motors and sensors placed in the multi-body model inside another specific simulator. So the 3D model in the multi-body software interactively responds to the actions performed by the user.

Keywords: CACE , CAE , Co-simulation , Design methodology , Mechatronics , Top-down design

Researchers in astrophysics and earth observation are still interested in balloon campaigns for making measurements outside the atmosphere. It is possible to trim a bit more from the ballooning costs by increasing the number of parts that can be reused, and by the careful design, the integration and the consolidation of a standard gondola apparatus (something like the mass production of cars). This paper will focus on one of the aspects capable of reducing costs, namely reusable power sources such as solar panels (SP) and fuel cells (FC) and how to protect them during the most difficult phases of the flight (take-off, landing). We will describe two possible ways of deploying and stowing a SP, and report the results of a thermal simulation aimed at ascertaining whether FC may be used in a stratospheric balloon environment.

The interest in LDB flights has grown dramatically over the years. However, since the success of a mission is strongly dependent on the costs, one possible way to improve the overall efficiency of a campaign is to perform different experiments during the same flight, even though this requires more versatile platforms. The design of this kind of system is very difficult to accomplish. In this paper the authors discuss the main issues related to the design of multi-experiment platforms for LDB flights, and try to provide some guidelines for making the approach more systematic. An application to a twoexperiment platform design problem is also briefly described.

The application of standard Information Extraction techniques to Patent Analysis has several limitations partially due to the difference existing between patents and web pages, which are the object of the biggest majority of information search. Indeed, while in other fields customized processing techniques have been developed, the number of studies fully dedicated to patent text mining is very limited and the tools available on the market still require a relevant human workload. This paper presents an algorithm to identify the peculiarities of an invention through an automatic functional analysis of the patent text; as a result a ranked list of components and functions is provided as well as a selection of meaningful paragraphs disclosing the details of the invention. An example related to laser irradiation devices for medical treatment clarifies its basic steps. © 2007 International Federation for Information Processing.

TRIZ, the Soviet-initiated Theory of Inventive Problem Solving, is gaining acknowledgement both as a systematic methodology for innovation and a powerful tool for technology forecasting. Nevertheless, the analysis of patents necessary for gathering the data to be used for the previsional activity is very cumbersome and sometimes unworthy due to the intrinsic low reliability of forecasting tasks. With this perspective it is necessary to speed up the identification of the technical/physical conflict(s) overcome by an invention, according to its textual description. Although text-mining tools have reached relevant capabilities for extracting useful information from huge sets of documents, no specific means are available to support the analysis of patents with the aim of identifying the contradiction underlying a given technical system. This paper proposes a computer-aided approach for accomplishing such a task: the algorithm is described and validated by means of practical examples. Copyright © 2007 Inderscience Enterprises Ltd.

Keywords: Analysis of contradictions , Patent analysis , Technology forecasting , Text mining , TRIZ

A numerical model, obtained by implementing a cyclic damage model in the framework of an interface element, is here proposed to reproduce the crack growth in laminated composites subjected to cyclically repeated loads. This model, which differs from the few studies in the literature on the topic, applies not only to single fracture modes but also to mixed modes, and to constant or variable crack growth rates. The applied load (in terms of force or displacement) is assumed to oscillate between a minimum and a maximum constant value. The Paris curve can be reproduced with accuracy once some parameters in the numerical model are tuned with experiments. These parameters are preliminarily found by simulating fatigue delamination in mode I (DCB test), in mode II (ELS or ENF test) and with a fixed mode mixture φ = GII/G (MMB test). A non-monotonic curve is then used to interpolate these preliminary results. Furthermore, tests where the mode mixture changes with crack length could also be reproduced. With this model it is possible to predict the crack growth rate with cycle of a generic structure without knowing a priori how the mode mixture φ changes during the crack propagation. This novel procedure gives a new opportunity in the design of composite structures subjected to repeatedly applied loads. © SAGE Publications 2007.

Keywords: Damage , Delamination , Fatigue , Finite element analysis (FEA) , Interface element

The behaviour of thin composite laminates (unidirectional, cross-ply and angle-ply) under compressive loads has been examined in cases where multiple delaminations are present. The problem is solved using the Finite Element Method (FEM) both with linear analyses, based on the eigenvalues research problem, and with nonlinear analyses, based on incremental-iterative procedures. In particular, the role of the delamination length, of the angle of the plies and of the stacking sequence on the critical load is investigated. Results are compared with those found in literature derived from experimental or numerical 2D analyses. © Freund Publishing House Ltd.

Keywords: Buckling , Composite laminates , Delaminations , FEM analysis

Experimental investigations and numerical simulations are performed in order to numerically predict the buckling behaviour of thin composite laminated specimens. Experiments are aimed at two objectives: the first is to completely characterize the carbon/epoxy material under simple loading configurations, the second is to test this material in buckling and post-buckling situations. The data collected with the first campaign of experiments are used to obtain the strength parameters required to define a damage model based on the failure theory by Tsai-Wu. This model is implemented in a Finite Element (FE) code and numerical simulations of buckling are executed for unidirectional and cross-ply laminates; results are in good agreement with experiments both in terms of determination of the critical loads and prediction of failure during post-buckling. © BME-PT and GTE.

Keywords: Mechanical properties , Modelling and simulation , Polymer composites

Creation of a CAD model from a hard model is something necessary for design modification, part replication or rapid prototyping and surface inspection. This is reverse engineering. Scientific literature presents many different approaches, even if, actually all the systems, mechanical (contact devices) and optical (non contact devices), work with constant acquisition pitches. This became a great deal in relation to the different object morphology combinations that the same surface could show. Working in fact with a constant pitch on a free-form surface it is possible to struggle with an insufficient points cloud density, when the acquisition pitch would be a compromise between the complex and elementary features that describe the object to acquire, or with an excessive points cloud density, when the acquisition pitch represents the highest scanner resolution. Referring to this situation, this paper proposes, starting from a first raw acquisition, an automatic methodology, directly implemented on the acquisition device, for the selective individuation of surface zones which present sensible curvature. In this approach the curvature of the measured surfaces is analyzed by defining a threshold over which it is necessary to perform a deeper scansion of the surface. In the present paper a methodology for the definition of the threshold value based on the measurement system uncertainty is described. In the current description the method is applied to an algorithm for curvature analysis, but it could be extended to any other approaches. Furthermore, it will be demonstrated that this new methodology is simple to apply and can be easily automated directly in the control scanner software. In the end of the paper a practical example is described in order to give an experimental validation of the method. © Springer-Verlag London Limited 2007.

Keywords: Design , Geometric morphology , Reverse engineering , Scanner 3D , Scanning strategy

Achieving a strict correlation between academic and industrial world is an important development direction in the engineering education field. The authors' first step along this path was the activation of several courses on methodical design, and the second step was the activation of a tight cooperation with industries, so that students could develop their thesis facing up to real problems. The fundamental advantages of this approach are: a) accustom the students to follow a design method; b) increase students' ability to find out and to consider "all" the possible solutions for a given problem, with the scope to choose the "best" one; c) increase students' ability to evaluate solutions' behaviour; d) possibility for the students to follow the production of the designed or modified machine. From the educational point of view, the two important aspects of this particular work are: a) The cooperation with the industrial world: the design was developed in cooperation with a company specialized in die-cutter machine production. The company realised and now produces a new machine based on this work. b) The application and integration of several design methods.

Keywords: Design education , Design methods , Die-cutting machine

A review of recent literature revealed a very high success rate of implants used to support a mandibular overdenture as an alternative to the conventional removable dentistry. Today there are already several prosthetic solutions for the same clinical situations: in particular, the implant support can be different depending on the type of implants used and their layout. It is well known that the success or the failure of implants interfaced with bone depends, taking into account a favourable biological reaction, on the structural condition of the biomechanical system constituted by the bone structure and the implant. Knowledge of the strain/stress pattern can allow one to establish if bone maintenance, resorption or addition is more likely to take place. In this work two different kinds of implant supports for overdenture retention were compared by means of FEM: they differed in the number of implants, their dimension, their location inside the mandible and, finally, in the presence/absence of a beam connecting all implants and making them all linked. Clinical follow-up was assessed by means of technetium 99m-MDP scintigraphy. The obtained results agree with the clinical experience.

Keywords: Biomechanics , Bone remodelling , Bone scintigraphy , Dental implants , FEM , Nuclear medicine

In the paper the design process, from the idea to the manufacturing aspects, with all the technical and technological problems, to develop a new competitive hard antitheft is described. The integrated use of the CAD/CAE and RP techniques made possible to analyse three different solutions in a very short time. The new model has completely designed, developed and patented (patent n. NA2005A000037) at the University of Naples and Cassino, Italy. It has weight and size very limited and some important features such as easiness to handle, high strength and high versatility; all this makes it an exclusive product of its type. The final product, made in AISI 1040 steel, is going to be manufactured and distributed in Europe by BULLOCK® in 2006.

Keywords: Antitheft , CAD , CAE , Lock system , Patent , PhD Researcher , RP Massimo Martorelli

The early identification of the optimal concept is a critical task of the design process in order to increase the chances of satisfying customers. The challenging aspect of the approach proposed in this work relies in the quality evaluation of virtual prototypes of new industrial products (i.e. concept designs) by adopting a statistical procedure previously applied to service industries. Following this approach, the optimal concept design is defined at the end of a process consisting of five phases: identification of the quality elements of the concept design, classification of the quality elements, generation and quality evaluation of product concepts and, finally, definition of the optimal concept. Currently, virtual reality (VR) environment offers the opportunity to evaluate the characteristics of different virtual prototypes by involving experts and/or customers, overcoming the need for several physical prototypes. On the other side, the dynamics of simulation and the stereoscopic visualization in VR environment provides a more realistic and impressive interaction with virtual prototypes than in CAD environment. The proposed methodology is fully exploited through two case studies: the choice of the optimal design for a traditional Neapolitan coffee maker, addressed by the Italian designer Riccardo Dalisi, and for a subassembly of a new minicar. © 2006.

Keywords: Concept design , Quality engineering , Virtual reality

Fade test results of ventilated disk brake rotor with pegs-wing performed by means of an inertia dynamometer, consisting of 14 repeated brake applications from an initial brake speed of 160 km/h down to 0 km/h, with constant deceleration are shown. The first brake application test results are compared to the FEM numerical predictions with MSC Visual Nastran on the ntire disk. These conform well to the experimental data, although numerical thermal field is slightly higher than the experimental one. Besides, ventilated disk brake rotor shows great dimensional stability and the ability to dissipate a great amount of thermal flow. © 2006 Inderscience Enterprises Ltd.

Keywords: brake temperature , disk brake rotor , fading testing procedure , finite element analysis , friction coefficient , thermal stress

The author presents an original algorithm aimed at automatically generating the hull shape of a sailing yacht starting from an initial set of parameters. The procedure consists of two steps. First one keel line and a Designed Water Line (DWL in the following) are faired according to a set of parameters, say length of water line, canoe body draft, stem angle and some adimensional coefficients. This information is then used to fair the hull surface, which must in turn fulfil more prerequisites (parameters like displaty cement, floatation area and related coefficients). The hull is defined by means of a B-spline surface, the fairing of which is ensured by allowing for all the imposed objectives and constraints. An optimisation technique based upon the gradient method ensures that a reliable solution is obtained in a very short time. © 2005 Elsevier Ltd. All rights reserved.

Keywords: CAD , Optimisation , Surface fairing , Yacht design

This paper presents methodology and guidelines about the use of process modeling languages to support BPR activities in relation with Product Development process. The methodology is based on the complementary adoption of different modeling techniques such as IDEF, UML and ARIS. Starting from the analysis of different models, we have selected and associated the most appropriate modeling suite to each phase of the re-engineering process. At this purpose, diagrams coming from IDEF, UML and ARIS families have been compared with respect to following issues: Degree of formality, completeness, simplicity vs. detail, capability to describe "business goal" and support to costing operations. © 2006 International Federation for Information Processing.

Keywords: ARIS , Business process re-engineering , IDEF , Process modeling , Product development process , UML