DEM-WCSPH Modeling of Hydroelastic Slamming

In this work, we present a numerical approach to tackle elastic fluid-structure interaction (FSI) cases, built within the Smoothed Particle Hydrodynamics (SPH) framework of DualSPHysics augmented with the multiphysics Project Chrono library. Within a homogeneous Lagrangian environment, the SPH particles constitute both the solid and fluid domains. The fluid dynamics behaves according to a WCSPH (Weakly Compressible SPH) method, whereas the structure particles move according to a properly developed rotational dynamic model. Flexible elements complying with the Euler-Bernoulli theory and discretized according to a lumped-elasticity formulation are used to reproduce the elastic behavior of a cantilevered beam and two double-clamped beams. The first validation for the presented approach is performed using the theoretical solution for the undamped free vibrations of a cantilevered beam. In addition, for validating its motion, a new theoretical solution is proposed to define the evolution of stress function in the cross sections of the beam, and the model provides exceptional compliance with the reference solution. Finally, the DEM-WCSPH scheme is validated through an FSI benchmark case of a deformable structure impacting still water, comparing solid displacement and fluid pressure time evolution with semi-analytical and a numerical solutions. The results obtained prove that DEM WCSPH coupling is an advantageous tool to approach complex multiphysics phenomena, with an interesting outlook regarding simulations of elastoplastic elements and fluid-driven structure collapses.