基于SHPB试验的岩石应变率效应分析

岩石材料在静荷载和动荷载作用下,其力学特性差异很大。采用直径100mm分离式Hopkinson压杆试验装置和波形整形技术对岩石进行动态冲击压缩试验,研究应变率范围为10~100s-1岩石的动态抗压强度、峰值应变及破坏形态的应变率效应。试验结果表明:试件动态抗压强度和峰值应变均随应变率增加而增大,最大动态抗压强度约为静态强度的2倍。试件动态破坏形态从低应变率下径向劈裂破坏到高应变率下粉碎破坏,随着应变率增加碎块数量明显增多而粒径变小,碎块粒径和块度分布变化显示出试件破坏形态具有明显的应变率效应。

Strain rate effect analysis of rock based on SHPB test

The mechanical properties of rock materials vary greatly under static and dynamic loads.In order to investigate strain rate effect of dynamic compressive strength,peak strain and failure mode of rock with strain rate vary-ing from 10-100 s -1 ,the dynamic shock compression test of rock is carried out by using the 100 mm diameter split Hopkinson pressure bar test device and waveform shaping technology.The test results show that the dynamic compressive strength and peak strain of the specimen increase with the increase of strain rate,and the maximum dynamic compressive strength is about 2 times the static strength.The dynamic failure modes of the specimens is from the radial splitting failure at low strain rate to the crushing failure at high strain rate,with the increase of the strain rate,the number of fragments increase significantly and the particle size become smaller.The variation of the particle size and the block distribution shows that the specimen failure modes have obvious strain rate effect.