Verification and application of 2-D DDA-SPH method in solving fluid–structure interaction problems

The study of fluid–structure interaction (FSI) is a challengeable topic, which concerns a coupled system with consideration of not only the behaviors of the fluid and the structure, but also the interaction process between both. In this paper a coupled method is introduced to simulate FSI problems in two-dimensional (2-D) case. In this coupled method (2-D DDA-SPH), the smoothed particle hydrodynamics (SPH) based on kernel approximation and particle approximation is employed to represent the fluid domain governed by Navier–Stokes equations and the discontinuous deformation analysis (DDA) based on the minimum total potential energy principle is used to model the real solid structure (with rigidity or elasticity) through virtual joints. A coupling scheme bridging both methods is used based on a penalty-force method, and an improved contact detection between particle and block is proposed. Several challenging examples, including breaking dam flow through an elastic plate, breaking dam flow on a rigid barrier or an elastic barrier are investigated to demonstrate the capability of the 2-D DDA-SPH method to capture the entire FSI process. Finally, two application examples, failure of gravity dam induced by water pressure, and dynamic response of armor blocks on breakwater under incident wave, are studied by using 2-D DDA-SPH. The simulation results show satisfactory agreements with available experimental, numerical, and analytical results, suggesting the applicability of the 2-D DDA-SPH method to solve FSI problems.