触地爆炸土体弹坑的多物质ALE法分析

Analysis of contact explosion-induced crater of soil using multi-material ALE method

为了研究触地爆炸下土体产生的弹坑,在LS-DYNA软件框架内,提出了基于多物质ALE法的岩土爆炸弹坑数值模拟方法。多物质ALE法综合了拉格朗日方法与欧拉法的优点,不但解决了拉格朗日法中材料的畸变问题,而且克服了欧拉法中移动边界描述得不准确的问题,而且容许在一个网格中包含多种材料。利用该法进行了岩土爆炸弹坑的数值模拟,在后处理中通过物质的流动状态来判断弹坑的形态,而无需通过单元删除或网格变形的方法。模拟结果与CONWEP程序计算值基本一致,弹坑的形成过程和最终尺寸都与客观规律吻合得较好,验证了多物质ALE法模拟岩土爆炸弹坑的有效性。

To study the contact explosion-induced crater of soil, the numerical technology was proposed in the frame of LS-DYNA based on multi-material arbitrary lagrangina-eulerian（ALE） method to simulate the blast-induced crater in geoteehnical medium. The multi-material ALE method combines the advantages of both the Lagrangian method and the Eulerian method, which not only avoids the mesh distortion in the Lagrangian method, but also overcomes the complexity caused by the moving boundary problems not well- described in the Euler method. What is more, it allows a variety of physical materials in an element. With this method, the numerical simulation of the blast-induced crater of soil was implemented, and the forma- tion of the crater could be observed in post processing by the flow of the material rather than the deforma- tion or deletion of the elements etc. The numerical results are basically coincident with the data of CONW- EP procedure, and the forming process and the ultimate form of the blast-induced crater agree well with objective law. All of these demonstrate that the multi-material ALE method is an effective way to simulate the blast-induced crater in geotechnical medium.