中文摘要：

为避免因采用实际装药结构导致网格精度难以保证,同时为减少因简化装药形状而造成模拟误差,针对LS-DYNA软件中的初 始体积分数法展开研究.首先对初始体积分数法进行了详细的介绍,接着通过两个典型的算例对该方法在多物质ALE算法和流固耦合 算法上应用的可行性进行了验证,最后将模拟值与传统方法及实测结果进行了对比.结果表明：用初始体积分数法模拟不同炸药形状对 水中爆炸冲击波超压峰值的影响,圆柱形和球形时的模拟结果互为接近,正方体模拟的结果相对偏大,其差距会随着比例距离的增加而 逐渐减小;该方法能够建立爆炸模拟中常见的1/2, 1/4甚至1/8球形或圆柱形装药模型,求解的结果精度较髙;对于需要考虑炸药不同 埋深的情况,建模时可先对炸药预定埋深的区域网格进行细化,再采用初始体积分数法调整炸药的位置,这样可减少重复建模的繁琐过 程,且能保证较髙的求解精度.

英文摘要：

In order to avoid the fact that the actual charge structurewas difficult to ensure the accuracy of the grid and reduce the simulation error caused by the simplification of the charge shape, the initial volume fraction method in LS-DYNA was studied. Firstly, the initial volume fraction method was introduced in detail. Then, two typical examples were given to verify the feasi-bility of the proposed method in the multi-material ALE algorithm and the fluid-solid coupling algorithm. Finally, the simula-tion results were compared with the results of traditional method and test measurement. The results showed that as for the effects of different shapes of explosive on the peak value of shock wave overpressure in underwater explosion, the simulated re-sults of explosives with cylinder and sphere shapes were close, while the cube simulation results was relatively large, the differ-ence may decrease with the distance to explosive. The method can be used to establish the 1/2, 1/4 and even 1/8 of model of sphere or cylinder charge in explosive simulation, and the accuracy of the solution is satisfying. For the case of different buried depths of explosive, the area mesh of the embedded depth of the explosive can be refined, then the initial volume fraction method is used to adjust the position of the explosion, which reduces the process of modeling and guarantees the higher accuracy of results.