爆炸气体驱动下岩体破裂的有限元-离散元模拟

在原有有限元/离散元（FEM/DEM）耦合分析方法中，实现了一种新的爆破计算模型。该模型考虑了在爆生气体的作用下，随着裂隙的扩展，气体占据的体积不断增大，气体压力逐渐减小这一问题。同时考虑了气体嵌入与爆腔联通的裂隙对裂隙的作用力。克服了原有FEM/DEM方法中的爆破模型仅仅将压力施加于爆腔四周的岩壁上，无法考虑爆生气体嵌入生成的裂隙对裂隙的作用。提出了一种新颖的贯通裂隙网络形成的递归搜索算法，只需通过编写一个简单的递归函数，即可实现复杂裂隙网络的搜索，采用一种简洁的方法完成了对复杂问题的处理。最后通过一个爆破算例，结果表明FEM/DEM方法可以对爆炸过程中应力波的传播及岩体中裂纹的萌生、扩展进行全程捕捉，展现了该方法用于爆破模拟的潜力。

Simulation of explosive gas-driven rock fracture by FEM/DEM

Based on original FEM/DEM coupling analysis method, a new model for blast simulation is implemented. The model considers increasment of the volume occupied by the gas and stable decrease in gas pressure with the expansion of cracks due to the blast gas embedding, and also takes into account the action of gas on the fissures linked at the explosion chamber. The limitation is overcome in the existing blasting model of FEM/DEM, where the pressure is only applied on the surface rock of blasting chamber without considering action of the embedded gas on the newly generated cracks. Meanwhile, a novel search algorithm of fracture network is proposed by compiling a simple recursive function for the search of complex fracture network; and a very simple method is used to handle the complex problem. Finally, a numerical example indicates that the improved FEM/DEM can simulate crack initiation and propagation of stress waves during explosion, showing a great potential of this method for the blast simulation.