中文摘要：

为研究高应变率下煤矿砂岩的动态拉伸性能,将岩样加工成厚径比为0.5的圆盘试件,利用直锥变截面分离式Hopkinson压杆（SHPB）试验装置,采用6种冲击气压对试件沿径向进行加载,实施不同加载速率的动态劈裂拉伸试验,测试试件的动态拉伸应力和应变率。试验结果表明：砂岩试件的动态劈裂破坏形态满足巴西圆盘试验有效性条件,试件内的径向应力分布达到应力均匀性要求;分析试验实测波形和应变率效应,得出高应变率下煤矿砂岩试件的拉伸应力和应变率特性。在试验采用冲击气压范围内,试件平均应变率由48 s-1增加至137 s-1,平均应变率与冲击气压近似为对数函数关系,动态拉伸强度与平均应变率近似为乘幂函数关系。

英文摘要：

In order to investigate the dynamic tensile performance of mine sandstone under high strain rate, variable cross-section split Hopkinson pressure bar（SHPB） apparatus is used to measure both the dynamic tensile stress and the strain rate of specimens. Rock samples are processed into disc specimens with the thick-diameter ratio of 0.5. Six impact pressures loaded in radial direction are applied in splitting tests to implement various loading speeds. The results show that not only splitting failure mode of tested specimens meets the validity condition in Brazilian disc test, but also radial stress distribution in specimen achieves the stress homogenization demand. Both the actuall measured waves and the strain rate effect are analyzed. The tensile stress and the strain rate of specimens under high strain rate are also studied. When the impact pressures are in the test range and the average strain rate increases from 48 to 137 s-1, the relationship between the average strain rate and the impact pressure is approximately an logarithmic function, and that between the dynamic tensile strength and the average strain rate is close to a power function.