Application of an SPH-DEM Coupled Model for Elastic Fluid–Structure Interaction

In this work, we present the application of an alternative numerical model for fluid dynamic analyses of structural systems within the Smoothed Particle Hydrodynamics (SPH) framework of DualSPHysics coupled to the Project Chrono library. The Discrete Elements Method-based (DEM) structure model relies on the Euler–Bernoulli theory and utilizes lumped elasticity and rigid body dynamics to reproduce the flexural behavior of two-dimensional beams. The structure and fluid domain are both discretized with SPH particles: the fluid dynamics obey a Weakly Compressible SPH (WCSPH) formulation, whereas the structure particles are assembled into DEM rigid elements, moving according to physically-based, properly developed rotational dynamics. The presented model is of interest for studying complex soil–, solid–, fluid–structure interactions, involving a system that includes all the aforementioned phases in a unitary context—very useful for studying engineered structures under the threat of hazardous natural events. Test cases are presented to validate the SPH-DEM coupled model in both accuracy and stability, starting from an equilibrium test, to the dynamic response, and ending with fluid–structure interaction simulations. This work proves that the developed theory can be used within a Lagrangian framework, using the features provided by a DEM solver, overtaking the intrinsic limitations, and hence applying the results of static theory to complex dynamic problems