基于SPH方法的大块煤冲击破碎数值模拟

Numerical simulation of impact breaking of large lump coal based on SPH method

为研究大块煤在钎杆冲击下的破碎效果,引入RHT混凝土本构模型材料来模拟大块硬煤(压缩强度35 MPa),并基于光滑质点流体动力学(SPH)方法建立了钎杆冲击大块煤的三维仿真模型。分析比较了大块在静压、纯冲击和冲压组合作用下的破坏程度,以及平头和圆锥形钎杆冲击效果的差异。仿真结果表明:平头钎杆在30 MPa压力、15 m/s速度或是其组合作用下,均无法使大块产生有效破坏;平头钎杆在200 m/s的超高速下可使大块产生彻体破坏,但实现钎杆高速运动困难;圆锥钎杆在30 MPa压力和15 m/s速度的冲压作用下,使大块产生了较大范围的锥形失效,远高于常规液压破碎锤的单次冲击破坏程度。锥形钎杆、高压高速是破碎硬质大块煤的一种有效方法,可在较少作用次数下实现破碎,验证了低频重载破碎大块的可行性。

In order to investigate the fracturing effect of large lump coal as crushed by impact rod, the RHT concrete constitutive model was introduced to simulate the hard coal, the compressive strength of which is 35 MPa, and the three-dimensional simulation model was built based on smoothed particle hydrodynamics （SPH）method. The damage degree of large lump under the action of static pressure, pure impacting and the combination of pressure and impac- ting, and the damage difference between flat head rod and conical rod were compared. The simulation results indicate that the flat head rod cannot break the large lump effectively with pressure of 30 MPa, velocity of 15 m/s and the com- bination action of them. The damage range of large lump is throughout the body under a 200 m/s flat head rod, but the achievement of super-high velocity is difficult. A cone damage zone is formed under a conical rod with 30 MPa pres- sure and 15 m/s velocity,and the damage range is larger than a common hydraulic hammer with the same rod diame- ter. Cone rod with high pressure and high velocity can destruct the large lump coal within fewer times, and it is verified that the low frequency and heavy load scheme of breaking large lump coal is feasible.