Numerical investigation of the dynamic response of CWC structures subjected to underwater explosion loading

The arbitrary Lagrange Euler (ALE) finite element method was used to simulate deformation and damage to a cylindrical shell-water-cylindrical shell (CWC) structure subjected to underwater explosion (UNDEX) loading. The experimental and computational results were in agreement, illustrating the validity of the computational scheme in complex fluid-structure interaction problems involving metals subjected to UNDEX loading. The dynamic process of UNDEX loading can be divided into four stages based on the deformation of and damage to the CWC structures. It was found that increasing the wall thickness of the inner and outer tubes and the thickness of the water sandwich significantly enhanced the overall protection provided by the CWC structure during UNDEX loading. When the sandwich was incompletely filled with water, the inner tube of the structure wrinkled owing to the large pressure difference between water and air at the interface of the sandwich. At a specific water-filled ratio, the large pressure difference inside the sandwich provided aggravated the deformation and damage of the CWC structure.