The internal substructure method for shock wave input in 2D fluid-structure interaction analysis with unbounded domain using doubly-asymptotic ABC

Abstract

Interaction between underwater shock waves and structures has attracted significant interest of many researchers. This study aims to develop a method to solve two-dimensional (2 D) fluid-structure interaction problems during far-field underwater explosion (UNDEX). The acoustic domain which can undergo small pressure variations is considered to describe the fluid-structure interaction during UNDEX. First, the empirical formula of the incident shock waves is considered as free wave motion of the fluid, and the fluid domain is Discretized by the finite element method. Based on the scaled boundary finite element method (SBFEM) and continued fraction solution, an artificial boundary condition (ABC) with high accuracy in time domain is adopted to simulate the truncated infinite domain, which can be placed very close to the radiating field is adopted to simulate the truncated infinite domain. Third, an internal substructure method (ISM) to calculate the equivalent input shock wave loads is proposed. Finally, the proposed method is used to study the scattered waves on a rigid circular structure due to the shock wave, and the effect of the radiation wave due to the motion of the structure on the dynamic responses of the circular structure during UNDEX is studied.