盐岩冲击特性试验研究

TESTING STUDIES ON RESPONSE BEHAVIOUR OF ROCK SALT TO IMPACTING

采用 SWT 方法,对盐岩在压剪联合冲击加载过程中的力学特性进行研究,通过跟踪材料动态损伤过程中材料剪切性能的变化,从而确定材料与动态损伤相关的特性。通过对盐岩在压剪联合作用下的不同速度的冲击试验研究,结果显示,当冲击速度高于 200 m/s 时,盐岩材料很快进入破坏阶段;当冲击速度为 70～200 m/s 时,盐岩材料处于动态损伤状态。并第 1 次发现一个非常有意义的现象,即与一般的脆性材料的冲击完全不同的是,盐岩在压剪联合冲击过程中除了常规的 4 道冲击波外,在卸载压缩波到来之前,还有 1 道卸载剪切波。

The response behaviour of rock salt under combined compression and shear impact loading are investigated by utilizing the S-Wave Tracing techniques, and correlative characteristics of dynamic damage are obtained by tracing changes of shear behavior during dynamic damage of rock salt. Impacting experiments with different impact velocities are conducted under combined compression and shear impact loading. Testing results show that (1) rock salt is in fracture phase when impacting velocity is more than 200 m/s, and (2) rock salt is in dynamic damage phase when impacting velocity is at 70-200 m/s. An important experimental phenomena is discovered for the first time in the impacting dynamic experiments, that is to say, there is another unloading shear wave before the unloading compress wave besides routine four impact waves in the process of compress-shear impact of rock salt, which is greatly different from other brittle materials.