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耦合SPH和FEM是一种有效岩石爆破损伤的数值模拟方法。本文建立了爆破损伤本构方程和爆破过程的SPH-FEM耦合算法,并利用此本构方程和SPH-FEM耦合法对无结合面和有结合面的2种岩石模型的数值模拟计算分析,研究获得了爆生裂纹发育规律和爆生气体对岩石的作用方式、过程和效果。研究结果表明:高压爆生气体先后经历高压膨胀并冲击孔壁、反射、再压缩、再膨胀冲击孔壁、再反射的反复过程,由此形成一系列膨胀波对岩石孔壁进行多次冲击;岩石内微裂纹的生成过程存在着7个关键时间节点,爆生气体对裂纹的发育和生长有4方面的影响:1)直接冲击孔壁形成破碎区和主要的径向裂纹;2)驱动这些径向裂纹生长;3)形成的应力波在岩石内部形成裂纹;4)应力波在岩石外表面反射和叠加形成裂纹并造成表面剥落。径向裂纹的生长速度要慢于应力波的传播速度,且其生长取决于4个影响因素。
Coupling SPH and FEM is a numerical simulation method for effective rock blasting damage. In this paper, the SPH-FEM coupling algorithm for the constitutive equation of blasting damage and the blasting process is established. The numerical simulation and calculation of two kinds of rock models with and without joint and SPH-FEM coupling method are studied. The developmental rules of the explosion and the effect mode, process and effect of the blasting gas on the rock are obtained. The results show that the high-pressure explosion gas undergoes high-pressure expansion and then impacts the hole wall, reflection, recompression, re-expansion of the impact hole wall, re-reflection of the repeated process, thus forming a series of expansion wave multiple impact on the rock wall; There are seven key time nodes in the formation of microcracks in the rock. There are four aspects to the development and growth of the crack in the blast gas: 1) directly impact the pore wall to form the crushing zone and the main radial cracks; 2) drive these Radial crack growth; 3) the formation of stress waves in the rock to form cracks; 4) stress waves in the outer rock surface reflection and superimposed to form cracks and cause surface flaking. The radial crack grows slower than the stress wave and its growth depends on four factors.