冲压工艺中几何及内圆角对模具应力产生的影响-毕业文外文翻译.docxVIP

附录A 外文文献Effects of geometry and fillet radius on die stresses in stamping processesAbstract: This paper describes the use of the finite element method to analyze the failure of dies in stamping processes. For the die analyzed in thepresent problem, the cracks at different locations can be attributed to a couple of mechanisms. One of them is due to large principal stressesand the other one is due to large shear stresses. A three-dimensional model is used to simulate these problems first. The model is thensimplified to an axisymmetric problem for analyzing the effects of geometry and fillet radius on die stresses. 2000 Elsevier Science S.A.All rights reserved.Keywords: Stamping; Metal forming; Finite element method; Die failure1. IntroductionIn metal forming processes, die failure analysis is one ofthe most important problems. Before the beginning of thisdecade, most research focused on the development of the-oretical and numerical methods. Upper bound techniques[1,2], contact-impact procedures [3] and the finite elementmethod (FEM) [4,5] are the main techniques for analyzingstamping problems. With the development of computertechnology, the FEM becomes the dominant technique[6-12].Altan and co-workers [13,14] discussed the causes offailure in forging tooling and presented a fatigue analysisconcept that can be applied during process and tool design toanalyze the stresses in tools. In these two papers, they usedthe punching load as the boundary force to analyze the stressstates that exist in the inserts during the forming process anddetermined the causes of the failures. Based on these concepts, they also gave some suggestions to improve diedesign.In this paper, linear stress analysis of a three-dimensional(3D) die model is presented. The stress patterns are thenanalyzed to explain the causes of the crack initiation. Somesuggestions about optimization of the die to reduce the stressconcentration are presented. In order to optimize the designof the die, the effects of ge