Coupled SPHS–BEM method for transient fluid–structure interaction and applications in underwater impacts

• Coupled SPHS–BEM method for transient FSI problems is proposed.
• The advantages of SPHS and BEM are integrated in the coupled method.
• Moving least square function is introduced to deal with the coupled surface.
• The coupled method is applied to solve underwater impact problems.

Coupled SPHS–BEM method is proposed for transient fluid–structure interaction problems: SPH shell (SPHS) is selected to discretize shell structures, the second-order doubly asymptotic approximations (DAA2) of boundary element method (BEM) is chosen to analyze flow-field. BEM can remedy the expensive costs for three-dimensional SPH (smoothed particle hydrodynamics), yet SPHS provides a structural solver for BEM. The coupled method is attractive, since only a layer of SPHS particles and a piece of flow-field boundary elements are needed to be modeled; the compatibility conditions of the coupled surface are performed with moving least square (MLS) function. The final two benchmarks on underwater impacts prove the feasibility, stability and accuracy of the proposed method.