动静组合载荷作用下岩石破碎数值模拟及试验研究

Numerical simulation and experimental investigation on rock fragmentation under combined dynamic and static loading

运用ANSYS软件对花岗岩在单一静载、动载和动静组合载荷作用下的破坏过程进行了数值模拟分析。结果表明:静载破岩时岩石中的裂纹扩展范围比冲击破岩时广,形成的破碎角大;冲击载荷破岩时岩石中的裂纹扩展速度比静载时快,形成的破碎角较小;动静组合载荷破岩时破碎深度和裂纹扩展面积比单一静载或动载时均大,破岩效果优于单一加载模式。在多功能岩石破碎试验装置上对花岗岩分别进行了单一静载、冲击载荷和动静组合载荷破岩试验,进一步表明动静组合载荷破岩在破碎深度、破碎体积和破岩比能方面比静力压入或单一冲击具有明显的优势,能大幅度提高破岩效果。不同的动静组合载荷存在不同的破岩比能,合理选取动静载荷的比值,可使破岩比能最小,破碎效果达到最优。

The numerical simulation method is applied to analysis the granite fragmentation process under static loading,impact loading and combined static and dynamic loading by ANSYS.The results show that the range of rock propagating cracks under static loading is wider and the angle of fragmentation bigger than that under impact loading;the crack growth rate in the rock under impact loading is faster than under static loading,which forms the smaller angle of fragmentation;the depth and area of rock fragmentation under combined loads are larger than static or dynamic loading and the crushing effect is better than the single loading model.By the multifunctional testing device for rock fragmentation,the breaking tests of granite under static loading,impact loading and combined static and dynamic loading are carried out.The test results further suggested that the breaking effects of rock are greatly improved under combined static and dynamic loading in the breaking depth,broken-volume and specific energy consumption compared with static loading and impact loading.The specific energy consumption of rock fragmentation is different for the different combined loading,reasonable ratio of dynamic loading to static loading can make the specific energy consumption least and breaking effect optimal.