岩石中强爆炸动力学过程数值模拟

NUMERICAL SIMULATION OF UNDERGROUND EXPLOSION IN GRANITE

在地下结构抗强爆炸作用的安全和防护研究中，需要对强爆炸的力学效应进行三维数值模拟。强爆炸的早期过程很复杂，在计算强爆炸的力学作用时一般可将其初始反应阶段结束时刻作为初始时刻，把强爆炸力学作用过程简化为铁蒸汽球等熵膨胀过程中对周围介质的作用。利用LS-DYNA^3D软件的用户自定义材料模型接口，将上述简化的强爆炸源作为一种独立的材料模型，实现了LS-DYNA^3D软件模拟强爆炸力学作用的功能。使用加入了强爆炸模型后的LS-DYNA^3D软件计算了花岗岩中强爆炸自由场应力波参数和空腔解耦强爆炸对壁面的压力，得到的结果与实测值和其他学者研究结果符合较好。研究结果为各种地下结构受强爆炸作用问题的三维数值模拟提供了计算工具。

The 3D numerical simulation of underground explosion is of interest for the protection of underground structures under explosion. The energy of explosion is sufficient to vaporize the medium around the work point. The expansion of the vaporized gas displaces the medium further out, causing deformation and failure. So the radiation transport and details of the very-early-time dynamics in the explosion source region are not considered in numerical calculations, and the energy source is modeled as an initially uniform spherical region of the appropriate energy content. A simple approximation is used for the vaporized gas, where the gas is assumed to consist of Fe and isentropic expansion of the gas is calculated. The suggested model is performed as a material model of LS-DYNA3D through its user-defined material function. Attenuation of radial peak stress and radial peak particle velocity of explosion in granite and the wall load function for decoupled explosive are calculated by using this material model. The numerical results are in good agreement with the experimental and numerical data achieved by other scholars.