基于SPH-FEM耦合法切缝药包爆破机理数值模拟

为了进一步研究切缝药包爆破机理,在AUTODYN内运用光滑粒子流体动力学与有限单元(SPH FEM)耦合法构建了装药不耦合系数为2.0的切缝药包爆破模型,分析装药爆炸初期的爆轰产物膨胀过程、爆轰产物粒子运动速度及炮孔周围岩体损伤演化历程。结果表明:对于切缝方向,由于没有切缝管的约束作用,爆轰产物粒子能够以较高的速度向前运动,粒子最大运动速度可达到4750m s^-1,最前端粒子在3.5μs到达孔壁,切缝方向岩体开始产生损伤破坏,且随着切缝管内爆轰产物的继续膨胀,切缝方向岩体进一步受到破坏;对于非切缝方向,切缝管的约束作用使得爆轰产物粒子膨胀受阻,粒子最大运动速度仅为800 m s^-1,同时切缝管在爆轰产物的推动下缓慢向炮孔壁运动,12.6μs切缝管到达炮孔壁,非切缝方向岩体开始产生损伤,但损伤展布区域较小,且非切缝方向炮孔壁保持了较好的完整性。

Numerical Simulation on Blasting Mechanism of Slotted Cartridge Based on Coupled SPH-FEM Algorithm

To further study the blasting mechanism of slotted cartridge,blasting model for slotted cartridge with a charge decou ple coefficient 2.0 was established by using coupled SPH FEM algorithm in AUTODYN.The expansion process of the detonation product in the early stage of the explosion,the velocity of detonation product particles and the damage evolution of rock mass around borehole were analyzed.Results show that the detonation product particles can move forward at high speed due to lack the constraint of slotted tube in the slit direction.The maximum velocity of the detonation product particles can reach 4750 m s^-1.The front end product particles reach the borehole wall and the rock mass starts to be damaged at 3.5μs.With the continuous expansion of detonation product,rock mass is further damaged in the slit direction.In the non slit direction,the ex pansion of detonation product particles is hindered due to the restraint of the slotted tube.The maximum velocity of particles is only 800 m s^-1.At the same time,the slotted tube driven by detonation products moves towards borehole wall slowly.The slot ted tube reaches the borehole wall and rock mass starts to be damage at 12.6μs.However,the small range of damage distribu tion is only formed,and the borehole wall maintains good integrity in non slit direction.