平头锥型回转体高速入水结构强度数值分析

为探究回转体在高速入水过程中的结构强度，基于非线性有限元LS-DYNA软件中流固耦合任意拉格朗日-欧拉(arbitrary Lagrangian-Eulerian, ALE)方法，分析了不同壁厚的回转体以100 m/s的初速度入水过程中的冲击力特性和结构强度。结果表明:数值计算得到的入水冲击压强峰值和速度衰减曲线与相应的理论值吻合较好，从而验证了数值方法的有效性；入水冲击载荷峰值出现在结构入水瞬间，结构入水后冲击载荷急剧变小且微小震荡；回转体的结构形式对其在高速入水过程中的结构强度有重要影响，尤其回转体头部厚度影响回转体结构强度，当回转体头部厚度为8 mm、后体壁厚大于2.5 mm时，可以保证回转体强度要求。

Numerical analysis on structural strength of a cone-shaped flatted revolution body during high-speed water-entry

In order to investigate the structural strength of a cone-shaped flatted revolution body during high-speed water-entry, based on the nonlinear finite element software LS-DYNA, which adopts the arbitrary Lagrangian-Eulerian (ALE) algorithm, the paper analyzes the characteristics of impact force and strength for the different structural revolution bodies with the initial velocity of 100 m/s. The results show that the peak impact pressure intensity and the velocity attenuation of the revolution body during water-entry agree well with the theoretical values, which can effectively verify the validity of the present numerical method. Besides, the peak value of the impact load occurs at the initial stage of the water-entry and the period is very short. After the revolution body enters the surface of the water, the impact load becomes smaller rapidly and changes slightly. The structural style of the revolution body has great effect on its strength during the water-entry, especially the head thickness of the revolution body. When the head thickness of the revolution body is 8 mm and the wall thickness of its afterbody is larger than 2.5 mm, the structure has no damage during the water-entry.