SHPB实验中试样形状和尺寸效应的数值模拟

Numerical simulation of effects of specimen size and shape in SHPB experiment

文章采用有效的方法讨论了动态接触算法中罚函数因子K的合理数值,在此基础上,利用LS-DY-NA3D有限元动力分析软件模拟了SHPB实验过程。对于不同的试样长度、直径以及不同环厚的环形试样,分别对模拟结果进行了应力-应变曲线重构;发现当试样与压杆横截面不匹配时,SHPB实验将产生较大的误差,尤其是对于环形试样;同时发现对于小直径试样的SHPB实验存在一个极限误差;研究结论将对SHPB实验中试样尺寸的确定提供借鉴。

The paper discusses the reasonable numerical value of the contact stiffness scale factor K for the dynamic contact algorithm by using effective methods. On the basis of this, the processes of the SHPB experiment are simulated by using the finite element software LS-DYNA3D. The stress-strain curve corresponding to the results of numerical simulation of the specimens, which are different in length, diameter and thickness of the annular shape, is reconstructed respectively. It is found that the mismatch of cross-sectional area of the specimen and the pressure bar will result in a greater error, es- pecially for the circular specimen, and a limit of the error exits for the small-diameter specimen. The conclusion of the study will give references to determination of the specimen size in SHPB experiment.