岩石材料动态破坏的近场动力学方法数值模拟

裂纹的聚集、扩展、分叉是岩石等脆性材料破坏失效的关键因素,本文在验证了近场动力学方法在研究岩石类材料裂纹动态扩展方面的有效性之后,采用近场动力学方法分别对冲击载荷作用下含有双裂纹岩石材料和单轴压缩作用下含单斜裂纹的岩石材料进行数值模拟.结果表明,对于双垂直裂纹,其裂纹扩展路径大致与预制裂纹成70°夹角;对于单裂纹,裂纹的扩展路径随裂纹倾角的变化而变化,最终导致构件的整体破坏.数值模拟结果表明近场动力学方法可以很好地模拟岩石等脆性材料的裂纹扩展直至破坏的过程,反映裂纹扩展的物理机理;其作为一种新的基于非局部理论的数值方法,在地下岩体工程方面及页岩气的开采方面会有很好的发展前景.

Numerical Simulation of Damage of Rock Materials Based on Peridynamics

Crack propagation, aggregation, bifurcation plays the key role in the failure of brittle materials such as rock. In this paper, after verifying the effectiveness of the peridynamics in studying the crack dynamic growth of rock materials, the numerical simulations of rock with prefabricated double cracks under impacting loading, and rock with the pre-notch single crack under compression loading are carried out by using peridynamics method. The results show that for the pre-notch double vertical crack, the crack propagation path is approximately 70°from the pre-notch crack. For the pre-notch single crack, the crack propagation trajectory changes with the crack orientation angle, finally resulting in the overall failure of the component. The numerical simulation results show that the peridynamics can well simulate the propagation of cracks in brittle materials such as rocks, up to the failure status, and reflect the physical mechanism of crack propagation. As a new numerical method based on the nonlocal theory, peridynamics has very good application prospects in underground engineering and shale gas exploration.