Abstract: Numerical analysis of metal cutting operations is increasingly relied upon in computer experiments, in order to clarify mechanical, thermal and tribological aspects in view of process optimization. The acid question is, however, whether impressive color displays and detailed figures describe what is actually taking place, or if some results might more properly belong to virtual reality. A classic experimental design for second order response surface work, concerning a simple cutting operation on mild steel, was run both in the metal cutting laboratory and on dedicated software, and results compared also in the light of classic models. Agreement concerning responses such as forces, temperature, and cutting ratio, was found to range from definitely fair to quite poor, underlining that reliance on numerical model may not always be fully justified. Analysis of deviations throws some light on a complex situation.
Keywords: Metal cutting | Numerical simulation | Turning experiments
Abstract: This paper concerns the automatic evaluation of Young's modulus of metallic materials. A procedure has been developed to support the experimental measurement process. A calculation scheme for an evaluation of the overall uncertainty of modulus value is presented according to ISO/IEC/OIML/BIPM guide published by ISO TAG4/WG3. Some numerical experimental results are also provided.
Keywords: Data acquisition | Metallic materials | Young's modulus
Abstract: Damage build-up leading to wire breakage occurring, either during the drawing process or delayed, causes quite a concern for manufacturers and users alike. In multipass wire drawing accumulated strain is known to lead to damage formation and further evolution which, if unchecked, may eventually trigger ductile fracture. However, even for such failures as can be traced back to the combined effect of initial material properties and process induced modifications, reliable assessment of relevant contributions is hardly an easy task at production floor level, and remedial action often relies heavily on cut and try methods.
Abstract: A tool-life model based on the assumption that wear and fracture are the causes of tool death is re-examined from the theoretical standpoint, and extended to include the effect of cutting speed on the fracture-induced failure rate. A stochastic model for multi-edge cutting tools is also proposed. This enables the overall statistics to be derived from the data for each individual cutting edge.
Abstract: Design data for a family of ring-shaped elastic elements are derived using analytical, numerical and experimental methods. The development of a family of elastic elements for load cells operating at medium to low level is considered in detail, using several approaches. The effects of thickness, boss size and fillet radius (reduced to non-dimensional form) on strain/load and deflection/load relationships are evaluated.
Abstract: A method developed for the attainment of economic objectives in single-tool machining operations is extended to multi-tool machining. The stochastic nature of tool life is taken into account, as well as the uncertainty of available information, by introducing confidence level for tool life. Time and cost penalties due to sudden tool failure are taken into account. An example shows that the minimum cost region falls well over the ninety per cent mark of confidence level for tool life.
Abstract: In some machining operations tools may fail suddenly in a catastrophic way. Multi-tool setups, where several tools are engaged simultaneously and a single tool failure may impair the whole operation, are particularly sensitive to such a failure mode. Selection of tool replacement strategy may then become a major problem, given a minimum amount of information, simple simulation methods help to assess alternative policies.
Abstract: Practical third order experimental designs, developed taking into account the requirements of calibration work, are presented in this paper. These designs are made up by a suitable combination of low order fractional factorials and a symmetric star. Design criteria and performances are assessed and the effects of experimental design on precision of estimation are analyzed.
Abstract: This paper deals with an experimental approach to the voltage-current relationship in the gap during electrochemical operations. Until now, information about the real form of the nonlinear law connecting these two variables has not been available. An experimental setup was built in order to readily collect data in a form suitable for further statistical analysis. Experimental data were obtained according to a factorial design of the 3**n series. Statistical analysis of the results led to a first approximation linear model. Analysis of residuals and theoretical considerations provided clues for a more sophisticated equation which yields a better fit.
Tieniti in contatto con
Per qualunque informazione non esitare a
contattare la Segreteria ADM tramite le modalità
previste nella sezione Contatti.
Se vuoi diventare membro dell'Associazione ADM, visiona
la pagina "Diventa Socio".
Iscriviti e sarai informato su tutte le
novità riguardanti l'Associazione