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

Abstract

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.