应力三轴度的有限元计算修正

对某高强度钢制成的光滑圆棒和缺口圆棒进行了系列准静态拉伸实验,采用ABAQUS对每个试件进行了数值模拟,得到了该材料的真实应力应变曲线,拟合出了J-C本构模型和失效模型的部分材料常数。最后,对该高强度钢制成的平板进行了撞击实验,并用得到的J-C模型对平板撞击实验进行了数值模拟,计算结果与实验结果吻合很好,证明利用数值模拟并修正应力三轴度的方法是可行的。

Updating of the stress triaxiality by finite element analysis

The stress triaxiality is the most important factor that controls initiation of ductile fracture,besides the strain level.Quasi-static tensile tests on smooth and notched specimens of high strength steel were carried out,and numerical simulations of the tests were performed using finite element code ABAQUS.Based on the experimental and numerical results,some material parameters of the Johnson-Cook constitutive model and the fracture model were obtained.Finally,rectangular plates made of the high strength steel were collided by dropping punch,and numerical simulations were performed using the Johnson-Cook model obtained previously.Good agreements were found between the tests and the numerical results,which illustrated that it was reliable to update the stress triaxiality by numerical simulations of tensile tests.