基于断裂力学的岩石切削数值分析探讨

Numerical analysis of rock cutting based on fracture mechanics

为研究岩石切削过程中刀具的力学特性以及刀具平均峰值作用力的预测,基于断裂力学和有限元理论建立了岩石切削的数值模型。模拟分析岩石对刀具的反作用过程,得到不同力学特性岩石和刀具作用条件下刀具所受的反作用力,结果表明,冲击速度在一定范围内对刀具平均峰值作用力影响较小;岩石体积呈阶跃性递减,刀具作用力大小与崩落岩石碎片体积变化一致。对模拟、实验以及已有理论计算得到的刀具平均峰值作用力进行线性回归分析,研究结果表明,数值方法计算结果与实验结果、Goktan[1]理论计算结果的线性相关系数分别为0.812、0.930,相关性较好,表明所建数值模型用于模拟岩石切削是正确和可靠的。

In order to study the mechanical characteristics of the cutter in rock cutting process and the prediction of mean peak force reaction on the cutter, a numerical model of rock cutting is established based on the fracture mechanics and finite element theory. The process of the rock reaction on the cutter is simulated and investigated; and the reaction forces on the cutter are obtained with different rock mechanical characteristics and impacting conditions of the cutter. The results show that the impacting velocity within a certain range has less effect on the peck cutting force, the variation of reaction force is unanimous to rock volume changes with stepwise decreasing. The relationship of mean peak force reaction on the cutter obtained from simulations, experiments and theoretical models is investigated with the linear regression analysis. The results show good correlations that the linear correlation coefficients between numerical results and the results of experiments and Goktan＇s theory are 0.812, 0.930 respectively; and it is indicated that this numerical model is 13rotter and feasible to simulate the rock cutting process.