一种散体材料SHPB被动围压试验体应力修正方法

本文利用有限元仿真给出了一种修正方法，并用数值仿真和试验验证了该方法的可靠性。研究表明：散体材料SHPB被动围压试验中，试样厚度远小于厚壁圆筒长度时，端部效应会导致厚壁圆筒不均匀凸出变形，计算材料的体应力-应变关系不能将厚壁圆筒应力状态简化为平面应力问题；厚壁圆筒处于弹性状态下，通过厚壁圆筒理论计算出的径向力与真实径向力存在一定比例关系，在一定范围内，折算系数与试样实时厚度呈二次函数关系。

A volume stress correction method for SHPB passiveconfined pressure of granular materials

Aiming to overcome the disadvantages and demerits in the stress calculation in the passive confinement pressure SHPB tests of granular materials, a numerical modified approach is proposed in the present paper. The modified approach is also verified by finite element numerical simulation and experimental results. The results show that when the length of specimen is much shorter than the length of thick-walled hollow cylinder, the edge effects will lead to a non-uniform distribution of deformation along the length of hollow cylinder. Therefore, the configuration of thick-walled cannot be simplified as a plain stress problem when calculating the stress and deformation state of granular material. Due to the fact that the thick-walled hollow cylinder is elastic, the real radial stress in the hollow cylinder is proportional to the theoretical predictions. The proportionality coefficient has a quadratic function relation with the length of specimen.