高压水射流破岩应力波效应的数值模拟

高压水射流破岩是一个涉及诸多因素的复杂的非线形动力学问题,利用非线形有限元法,采用动态接触模拟高压水射流对岩石冲击作用.结果显示岩石内部最初受到冲击时的不稳定性由强变弱,反映了岩石的动态响应特性;模拟了在不同冲击速度下应力波在岩石中的传播和衰减过程,结果表明应力波的传播速度与冲击速度成正比,射流速度越大,应力波衰减越快;同时还模拟了以相同的速度分别冲击砂岩和煤时的应力波效应,计算表明在相同的冲击速度下,射流冲击煤的局部性效应比冲击砂岩时更为显著,应力波在砂岩中的传播范围要广泛一些.

Stress wave effect in numerical simulation on rock breaking under high pressure water jet

The evolvement of rock damage struck by a high-pressure water jet is characterized by nonlinear properties,thus making it a complicated dynamic problem.Based on a nonlinear finite element and elastic-plasticity theory,a computational model was established.The dynamic load striking the rock by a high-pressure water jet was simulated by the dynamic contact method.Furthermore,the propagation of a stress wave in the same rock was simulated at different impact velocities.The results show that the propagation velocity of a stress wave is proportional to the impact velocity of the high-pressure water jet.The effects of a stress wave in sandstone and coal impacted by high-pressure water jets of the same velocity were simulated.The effect of a stress wave in coal was stronger than in sandstone,while the region of propagation of stress wave in coal was smaller.