SHPB恒应变率加载试验技术研究

Study on SHPB Techniques of Constant Strain Rate Loading

基于对SHPB试验系统数据处理原则和SHPB试验装置在岩石材料中应用条件等问题的全面分析,得出了实现恒应变率加载能够有效地解决SHPB试验装置在进行岩石类材料冲击试验中存在的应力不均匀和弥散效应等问题的结论;确定了柱锥形子弹是实现恒应变率加载的有效手段;对总长400mm的柱锥子弹的不同形状参数进行模拟分析,得出了实现花岗岩恒应变率加载的最优柱锥子弹大小端面比为0.7,试件长径比为0.75~0.82,子弹最优锥长为300 mm.通过与传统圆柱子弹加载波形对比,从数值模拟和试验两个方面验证了所设计的柱锥形子弹实现了对花岗岩恒应变率的冲击加载.

Constant strain rate loading could effectively solve the stress uniformity and the dispersion effect of the SHPB device in the application of rock-like materials based on a comprehensive analysis of the testing technology on the SHPB data processing principle and the conditions which SHPB device applied in rock material.It was determined that conical-cylindric bullet was an effective way to realize constant strain rate loading.An analysis of different shape parameters was made by means of numerical calculation for the total length of 400 mm conical-cylindric bullet.It was seemed that the optimal area ratio between small end-face and large end-face was 0.7,and the specimen length-diameter ratio of granite was between 0.75 and 0.82.The optimal cone length of the bullet is 300mm.By comparing the waveform with traditional cylindrical bullets,it was proved that the designed conical-cylindric bullet could achieve the constant strain-rate loading of granite was verified from two aspects of numerical simulation and experiments.