A Coupled FDEM–SPH Model for Simulating Problems of Fluid–Solid Interaction

This paper introduces the FDEM–SPH model, which combines the strengths of FDEM to simulate solid deformation, fracture, and fragmentation and SPH to simulate fluid flow. The coupling of these two methods is achieved through dynamic boundary conditions at the fluid boundary and the application of fluid forces at the solid boundary. The accuracy of the SPH code is validated through the dam collapse test, while the correctness of the FDEM–SPH model is confirmed by the hydrostatic pressure and floating object test, and Scott Russell's wave generator. The FDEM–SPH model is then utilized to simulate hydraulic fracturing and deformable landslide surges. Unlike existing FDEM-based hydro-mechanical models, which are limited by the connection relationship between the joint element and the triangular element, the FDEM–SPH model overcomes this limitation and is capable of simulating large-scale fluid–solid interaction problems, such as large-aperture hydraulic fracturing, landslide surges, water entry, et al.