Numerical simulation and experimental examination of forming defects in multi-point deep drawing process

摘要

Significant reductions in manufacturing costs are required to make structural material attractive for mass production applications such as automotive components. This can be achieved through highly efficient multi point forming operation, which has proven its ability to produce metal products with very good structural integrity and quality. This paper aims at studying forming defects which occur in multi-point deep drawing method through simulation and experimentation. In this study, commercially available finite element software ABAQUS / EXPLICIT 6.14.1 was used for the simulation of forming procedure. In order to analyze sheet behavior in multi point deep drawing procedure and also representing defects which may happen during the forming process, three-dimensional models will be utilized. The experimental tests were carried out through using Sheets of aluminum alloy 2024 with an initial size of 300?×?300?mm. Defects created in the multi-point forming process was investigated and rupture of forming sheet was predicted by using ductile fracture criteria. Studying blank holder force for Polyurethane layers with different hardness reveals that blank holder force increase has a direct relation with the increase in polyurethane layer hardness. The results of simulation depict that by increase in the thickness of polyurethane layer, the rate of indentation is reduced. By comparison of the Cockcroft – Latham and Clift criteria of each element, it is seen that elements which are related to Clift criterion reach to rupture earlier.