Comparative study of six failure criteria via numerical simulation of stamped DP600 steel

Abstract

During the development of an automobile part obtained by stamping process, time and money are required aiming process planning and set up of a new tooling. One of the difficulties in stamping is to know if the chosen material will have sufficient formability to reach the final form required by the project. Because of this difficulty it is very interesting to propose a method that can accurately simulate the forming process. The failure criteria can be mathematical or empirical models capable of determining the onset of necking for each stress/strain states. It is interesting to find a failure criterion that can be easily determined and provides a good ability to detect the failure accurately. In this study six different failure criteria were studied. Five of them are classified as ductile damage models and they depend on the stress triaxiality and plastic strain. The last criteria depend only on the deformations in the main directions and it is called the forming limit curve (FLC). It was used computational models through finite element analysis (FEA). The formability was evaluated by monitoring the displacement of the punch until the failure of the material. Some failure criteria have been able to provide approximation errors in the range of 0.7 - 5% which makes them interesting for practical implementation in the industry.