Search results for "Forming"
showing 10 items of 1719 documents
Opportunity of metallic interconnects for ITSOFC : Reactivity and electrical property.
2006
International audience; Iron-base alloys (Fe-Cr) are proposed hereafter as materials for interconnect of planar-type intermediate temperature solid oxide fuel cell (ITSOFC); they are an alternative solution instead of the use of ceramic interconnects. These steels form an oxide layer (chrornia) which protects the interconnect from the exterior environment, but is an electrical insulator. One solution envisaged in this work is the deposition of a reactive element oxide coating, that slows down the formation of the oxide layer and that increases its electric conductivity. The oxide layer, formed at high temperature on the uncoated alloys, is mainly composed of chromia; it grows in accordance …
A New Numerical Method for Axisymmetrical Forming Processes
1987
Summary In this paper a numerical method for the analysis of axisymmetrical forming processes is proposed. This method represents the last development of a previous one which allows to solve forming problems in plane strain condition. The proposed model is baaed on the finite element discretization and on the linearization of the yield surface which leads to solve a LP problem. Two different examples of application, concerning the upsetting of a cylinder and of a hollow disk are reported.
Moving Least Squares Innovative Strategies For Sheet Forming Design
2011
In the last years a great interest in optimization algorithms aimed to design forming processes was demonstrated by many researches. Proper design methodologies to reduce times and costs have to be developed mostly based on computer aided procedures. Response surface methods (RSM) proved their effectiveness in the recent years also for the application in sheet metal forming aiming to reduce the number of numerical simulations. Actually, the main drawback of such method is the number of direct problem to be solved in order to reach good function approximations. A very interesting aspect in RSM application regards the possibility to build response surfaces basing on moving least squares appro…
A contribution on the optimization strategies based on moving least squares approximation for sheet metal forming design
2012
Computer-aided procedures to design and optimize forming processes are, nowadays, crucial research topics since industrial interest in costs and times reduction is always increasing. Many researchers have faced this research challenge with various approaches. Response surface methods (RSM) are probably the most known approaches since they proved their effectiveness in the recent years. With a peculiar attention to sheet metal forming process design, RSM should offer the possibility to reduce the number of numerical simulations which in many cases means to reduce design times and complexity. Actually, the number of direct problems (FEM simulations) to be solved in order to reach good functio…
A NEW PROGRESSIVE DESIGN METHODOLOGY FOR COMPLEX SHEET METAL STAMPING OPERATIONS: COUPLING SPATIALLY DIFFERENTIATED RESTRAINING FORCES APPROACH AND M…
2010
The growing interest in sheet metal stamping processes, particularly in the automotive industry has led to three main issues in this field:*request of very complex shapes; *growing interest in springback control; *solution of multi-objective problems. These issues make a sheet metal stamping processes design very difficult and proper design methodologies to reduce times and costs are highly required. In this paper, a computer aided approach aiming to satisfy the mentioned issues is proposed. In particular, a progressive design approach based on the integration between numerical simulations, Response Surface Methodology (RSM) and Pareto optimal solutions search techniques was applied in orde…
Multi Stage Strategies for Single Point Incremental Forming of a Cup
2008
A five stage forming strategy for Single Point Incremental Forming of a circular cylindrical cup with a height/radius ratio of one is presented. Geometrical relations are discussed and theoretical strains are calculated. The influence of forming direction (upwards or downwards) is investigated for the second stage comparing explicit FE analysis with experiments. Good agreement is found between calculated and measured thickness distribution, overall geometry and strains. Using the proposed multi stage strategy it is shown possible to produce a cup with a height close to the radius and sides parallel to the symmetry axis in about half of the depth.
Error Estimates and Automatic Adaptive Mesh Refinement for the Metal Forming FEM Analysis
1988
The Authors propose a new technique which enables a estimation of the error inherent with the FEM analysis of metal forming processes. The aim is to evaluate the zones where the error is higher in order to proceed to a refinement of the mesh in such zones, and to obtain a smaller value of the global error. Moreover, to simplify the analyst work in the progressive refinement of the mesh, it has been prepared a software able to read the drawing created by a CAD program and to generate, automatically, all the geometrical and topological data necessary to perform the analysis on Personal Computer. The automatic renumbering of the elements in the refined mesh has been performed with the aim to r…
Common defects of parts manufactured through single point incremental forming
2021
Single point incremental forming is one of the most intensely researched die-less manufacturing process. This process implies the usage of a CNC equipment or a serial robot which deforms a sheet metal with the help of a relatively simple tool that follows an imposed toolpath. As every cold metal forming process, besides the many given advantages it has also some drawbacks. One big drawback in comparison with other cold metal forming processes is the low accuracy of the deformed parts. The aim of this research is to investigate the sheet metal bending mechanism through finite element method analysis. The results shows that the shape of the retaining rings has a big influence over the final g…
Diverse histories, common ground and a shared future:the education of career guidance and counselling professionals in the Nordic countries
2019
The development of education programmes in career guidance and counseling (CGC) has followed different paths among the various Nordic countries. Ten CGC programmes in Denmark, Finland, Greenland, Iceland, Norway and Sweden were evaluated against the NICE curricular model. The results show that all NICE core competences are represented in the curricula. However, there is greater focus in some programmes on developing competences for individual career guidance, than on developing competences for working at organisational and societal levels. Implications for the cooperation and professionalisation of CGC within the Nordic countries are discussed as well as limitations of the NICE model. Keywo…
Evaluation of Guidance Services in Higher Education in Finland
2003
The Finnish Higher Education Evaluation Council (FINHEEC) implemented an evaluation of guidance services in higher education in 2000–2001. Altogether 25 higher education institutions participated in the evaluation. This article describes the evaluation process, findings and recommendations. The aim is to show how an evaluation process can serve the development of guidance policies and practices at the institutional and national levels. Additionally, the article demonstrates the use of evaluation methodology as a means of enhancing communication between staff and students.