滚刀滚动切削岩石的数值及试验研究

为了研究滚刀滚动切削岩石的性能,合理简化盘形滚刀滚压破岩过程,采用颗粒离散元法分别建立了考虑摩擦力的滚刀滚动切削有、无节理岩体模型,分析了滚动切削模拟过程中切削力、裂纹发育、岩石破碎形态的变化规律.利用滚刀回转切削试验台进行了破岩试验,得到切削力随工况变化的规律,验证了仿真模型的准确性.研究结果表明:对无节理岩体,提高贯入度会增加主干裂纹深度和破碎面积,提高切削速度会增加法向力,而对滚动力影响不大;对含节理岩体,岩体节理强度越强则主干裂纹越深,比能耗越高;岩体的节理倾向会对破岩比能耗产生一定的影响,正向倾角切削效率高于逆向倾角约12%;节理倾角越小,正、逆向节理倾角破岩比能耗差值越大;合理安排刀盘正反转可提高破岩效率.

Numerical and Experimental Study on Rock Breaking by Cutter in Rolling Mode

To study the cutting performance of disc cutter during breaking rock, the practical process of breaking rock by disc cutter was simplified. The particle discrete element method was employed to build two-dimensional numerical models considering friction when disc cutter broke the jointed rock and intact rock. The variation of cutting force, crack growth and rock breaking format in the simulation were analyzed. Rotation cutting test bench was adopted to conduct rock breaking experiments, the changing and the recorded cutting force of cutter was compared with the simulation force to verify the numerical model. The study can be concluded as follow: For intact rock, the increase of the cutter penetration can increase the main crack depth and rock breaking area, and the increase of the cutting speed can increase the cutter normal force but have little influence on the rolling force. For jointed rock, higher joint strength leads to higher crack depth and cutting efficiency. The joint direction of rock has a certain impact on the specific energy of rock breaking, and the rock breaking efficiency for forward direction jointed rock is about 12% higher than that for the reverse direction jointed rock. Lower joint angle leads to bigger specific energy difference between forward and reverse direction. Reasonable selection of the cutter head rotating direction can improve rock breaking efficiency.