关键词: 新能源动力电池包；应力三轴度；箱体挤压失效；数值分析

Abstract: A method based on generalized incremental stress state dependent damge model (GISSMO) material fracture criterion and LS-DYNA software for finite element analysis is proposed to establish an experimental numerical model, against the large-area material tearing failure behavior of new energy power battery pack crush. Through the design of failure physical samples, uniaxial tensile and bulging test of materials are carried out to calibrate the failure plastic strain values under different stress triaxial states, and the cumulative damage parameter is also introduced to consider the effect of cumulative damage factors. By three point bending experiment is used to correct the material failure constitutive model, and comparing the results of pack crush experiment and simulation, it is found that the failure area, location and process failure behavior of materials have good consistency, and the force-displacement curve of crush has a high coincidence. It is proved that the failure calculation model based on GISSMO material fracture criterion obtained in this paper can accurately predict the crack generation and material failure when the power battery pack is squeezed and destroyed.

Key words: New energy power battery pack; Stress triaxiality; Box crush failure; Numerical analysis