基于SHPB试验的岩石动态力学响应分析

Study on Dynamic Response of Rock Based on Split Hopkinson Pressure Bar Test

采用分离式霍普金森压杆试验系统对砂岩进行冲击压缩试验,得到了砂岩的动态冲击压缩应力-应变曲线,研究了砂岩在冲击荷载作用下的动态力学响应,分析了砂岩的动态抗压强度、峰值应变及冲击破碎后的粒径分布等随应变率的变化规律。试验结果表明:在冲击荷载作用下,应变率对砂岩的力学行为有很大的影响,随着应变率的升高,砂岩的动态抗压强度及峰值应变均有较大程度的提高,表现出明显的应变率效应;砂岩破坏后的粒径分布呈现渐进性变化,大体分为三种类型,对岩石试件破坏后的粒径和块度分布进行研究能很好的表征试件破坏后的状况。

To understand the dynamic mechanical response of sandstone, a dynamic impact compression test was carried out by using split Hopkinson pressure bar apparatus. The dynamic impact compression stress-strain curve was obtained. The variation of dynamic compressive strength, peak strain and particle size distribution with strain rate were analyzed. The results show that under the impact load the strain rate has a great impact on the mechanical be- havior of sandstone, and as the strain rate increases, the dynamic compressive strength and peak strain are greatly improved. The particle size distribution of rock sample presents progressive change and can be divided into three types. The study on particle size distribution of rock sample can reflect the characterization of the specimen after damage.