一种考虑局部颈缩及损伤演化的改进失效准则在铝合金板冲击有限元分析中的应用

Application of an improved failure criterion considering local necking and damage evolution in finite element analysis of aluminum alloy plate impact

为快速准确分析铝合金结构在不同冲击载荷作用下的损伤断裂行为,提出了一种由局部颈缩准则和损伤演化模型相结合的、参数易于校准且适用于粗网格的改进失效准则。采用Fortran语言将自定义失效准则嵌入到LS-DYNA程序中完成二次开发,实现了改进的失效准则在数值仿真中的应用。通过对比分析九组试验与仿真结果,验证了改进的失效准则的适用性和准确性。研究结果表明,改进的材料失效准则具有较低的网格依赖性,能够很好地预测铝合金板的塑性破坏程度,可为铝合金结构冲击强度分析提供技术支撑。

Here,to quickly and accurately analyze damage and fracture behavior of aluminum alloy structure under different impact loads,an improved failure criterion combining local necking criterion and damage evolution model was proposed,it was easy to calibrate parameters and suitable for coarse grids.Fortran language was used to embed customized failure criterion into LS-DYNA program for secondary development,and realize application of the improved failure criterion in numerical simulation.By contrastively analyzing 9 sets of test and simulation results,the applicability and correctness of the improved failure criterion were verified.The study results showed that the improved material failure criterion has a lower grid dependency and can effectively predict plastic failure degree of aluminum alloy plate to provide technical support for impact intensity analysis of aluminum alloy structure.