2D Combined Finite Element/Material Point Fluid-Structure-Interaction Method And Its Application In Underground Explosion Simulation

In modern war,military facilities which have important strategic significance usually lie under the ground deeply.The penetration weapons are important equipment for destroying these underground facilities or structures.So the research of the underground explosion effects of penetration weapons has great significance for the evaluation of the weapon's effectiveness and the safety of the underground structures.Because of the complexity and the limitation of theory and experiment study,the numerical simulation becomes an important measure to study the underground explosion effects.In the simulation of underground explosion,the calculation of the fluid-structure interaction between donation products and rock-solid medium is the key process of the problem.The present work makes fully use of the respective advantages of finite element method(FEM)and material point method(MPM)where FEM computes the response of rock-solid medium and MPM computes the flowing behavior of the detonation products.And the combined finite element/material point method(FEM-MPM)is improved and applied in the research of the underground explosion effects of penetration weapons.The results show that the shock wave generated by the explosion of penetration weapon is anisotropic,and the peak pressure value of the shock wave in different directions are different,but this difference will decreases with the increase of the propagation distance.The initial different pressure in the underground rock-solid medium will not remarkably influence the propagation of the shock wave,because the initial pressure caused by gravity is slight to the one caused by the explosion.The present work provides a new method of numerical simulation for the underground explosion,which can well describe the phenomenon of underground explosion,and provide support the protection of deeply underground facilities.