基于SPH方法的柱状装药爆炸扩腔数值模拟

在LS-DYNA框架内建立基于SPH方法的柱状装药爆炸扩腔数值模型,克服有限元法或有限差分法在处理爆炸近区大变形和不连续问题的弊端,模拟了柱状装药起爆时岩石内部爆腔的形成过程,并对内部质点的压力和位移变化规律进行分析。结果表明:SPH方法能够较好地模拟柱状装药爆炸时岩石爆腔的形成过程,在处理爆炸近区具有一定优越性。柱状装药反向起爆后,在岩石中引起强烈的爆炸应力波,应力波波阵面近似成椭圆形;炸药底部的3个SPH粒子压力在短时间内达到峰值,然后逐渐振荡衰减;爆炸扩腔完成时间大约是500μs,爆腔呈椭球形,直径大约是16cm。

Numerical simulation of cylindrical charge explosive expanding cavity based on SPH method

In LS-DYNA framework,the numerical model of cylindrical charge explosive expanding cavity was established based on SPH(Smoothed Particle Hydrodynamics)method.The drawbacks of finite element method and finite difference method were overcome in dealing with the large deformation and discontinuous problems in explosion near area.The formation process of the explosive cavity inside the rock was simulated when the cylindrical charge was detonated.And the law of the pressure and displacement of the internal particles were analyzed.The results showed that the SPH method could simulate the formation process of the rock explosion cavity well during the explosion of cylindrical charge and it had a certain advantage in dealing with the explosion near area.After the cylindrical charge inverse initiation,strong explosion stress wave was caused in the rock,and the stress wavefront was approximately elliptical.The three SPH particles at the bottom of the explosive reached the peak in a short time and then gradually oscillated and attenuated.The completion time of explosive expanding cavity was about 500 μs.Explosive cavity was an ellipsoid and its diameter was about 16 cm.