新能源动力电池包箱体挤压失效数值分析

Numerical Analysis of Crush Failure of New Energy Power Battery Pack

针对新能源动力电池包箱体在挤压时,出现的大面积材料撕裂失效行为,提出一种基于广义增量应力状态依赖性损伤模型(GISSMO)材料断裂准则,采用LS-Dyna软件进行有限元分析建立实验数值模型的方法,通过设计失效物理样件,开展材料单向拉伸实验、胀形实验,标定不同应力三轴度状态下的失效塑性应变值,同时引入累积损伤参数以考虑累积损伤因素的影响。运用三点弯曲实验,矫正材料失效本构模型,通过比对箱体的挤压实验与仿真模拟结果,发现材料的失效区域、位置及过程失效行为均有较好的一致性,挤压力位移曲线的吻合度较高,验证了所得的基于GISSMO材料断裂准则失效计算模型,可以准确预测动力电池包箱体受到挤压破坏时产生的裂纹产生、材料失效问题。

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.