楔形刀具侵入岩石损伤破坏影响因素的理论分析及数值模拟

Theoretical analysis and numerical simulation of rock damage and failure under wedge cutting

通过空腔膨胀理论研究楔形刀具几何参数(刃角)、岩石力学参数(抗压强度、泊松比)对刀具与岩石接触面下岩石弹-塑性交界面半径的影响。结果表明:刀具与岩石接触宽度一定时,刃角越小,岩体的损伤区域越大,从而导致弹-塑性交界面半径增大。在其他因素不变的前提下,岩石泊松比增大或者抗压强度增加都导致弹-塑性交界面半径减小。采用参数敏感性分析方法对3种影响因素的敏感性进行了分析,在接触宽度一定的条件下,刃角的大小对弹-塑性交界半径的影响最大。采用ABAQUS软件建立刀具侵入岩石的数值模型,研究表明,刃角的变化对文中定义的岩体内最大拉应力点空间位置以及最小梯度方向有着显著影响。

Based on the cavity expansion theory, the influences of the geometric parameter （edge angle）, the rock mechanical parameters （compressive strength and Poisson＇s ratio） on the radius of elastic-plastic interface in rocks under wedge cutting conditions are studied. The results show that the smaller the blade angle, the larger the damaged area and the larger the elastoplastic radius when the contact width between the blade and rock is constant. When the other factors remain unchanged, the increase of the Poisson＇s ratio or the increase of the compressive strength leads to a decrease in the radius of elastoplastic interface. The sensitivity of the three factors is studied by the sensitivity analyzing method. Under a certain contact width, the blade angle has the most significant influence on the damaged area. A numerical model of the penetration of indentation is developed by using the software ABAQUS. The numerical results show that the changes of the blade angle can significantly influence the spatial position of the point with the maximum tensile stress and the direction of minimum gradient.