Violent Fluid-Structure Interaction simulations using a coupled SPH/FEM method

The Smoothed Particle Hydrodynamics (SPH) method presents different key assets for modelling violent Fluid-Structure Interactions (FSI). First, this method is a meshless method, which drastically reduces the complexity of handling the fluid-structure interface when using SPH to model the fluid and coupling it with a Finite Element Method (FEM) for the solid. Second, the method is Lagrangian and large deformations of the fluid domain can thus be followed, which is especially interesting for simulating violent interactions in presence of a free surface, or which induce large deformations, rotations, and translations of the solid. Third, the SPH method being explicit, the time scale of the SPH resolution in the fluid domain is naturally adapted to the FEM resolution in the solid. Free-surface FSIs can also be simulated without including the air phase when it does not play a significative role. For violent interactions where the fluid compressibility matters, it is also intrinsically modelled by the SPH method. The paper details the SPH method used and the coupling. The FEM solver is a standard open source solver for solid mechanics. Validation test cases are then presented in detail. They include the hydrodynamic impact of elastic wedges at high speed, where local pressures and wedge deformations are compared to experimental data.