关键词: 各向异性损伤, 镁合金板材, 失效预测, 数值模拟, 温热冲压

Abstract: Based on the frame work of the continuum damage mechanics, the prediction of damage evolution in a thermal stamping process of magnesium alloy sheet has been carried out by means of the finite element simulation, and the numerical results have been compared with the related experimental data. An anisotropic yield function for cold rolling sheet metals and an anisotropic damage theory are implemented into the ABAQUS user material subroutine VUMAT to predict the evolution of damage in the mentioned process. Taking a thermal stamping process of a phone shell for example, under the different working temperature, the overall anisotropic damage process from crack initiation to final propagation in local area of workpiece is proposed. Numerical results show that the prediction both of the site of crack initiation and the orientation of crack propagation are consistent with the data recorded in thermal stamping tests. It may be concluded that the proposed anisotropic damage model and the corresponding anisotropic yield function can be effectively incorporated into the finite element method(FEM) user material subroutine to predict the phenomenon of cracking during thermal stamping process of sheet metals.

Key words: Anisotropic damage, Failure prediction, Magnesium alloy sheet, Numerical simulation, Thermal stamping