A coupled peridynamics–smoothed particle hydrodynamics model for fluid–structure interaction with large deformation

Fluid–structure interaction (FSI) is ubiquitous in various engineering disciplines, and effectively managing FSI often appears to be the key for successful failure analysis and safety-oriented design. Smoothed particle hydrodynamics (SPH) serves as a potent nonlocal meshfree method for fluid dynamics modeling, while peridynamics (PD) demonstrates exceptional capability in addressing structural dynamics involving large deformations and discontinuities. Thus, leveraging their respective strengths in a combined approach holds significant promise for tackling FSI challenges. In this work, we propose a new peridynamics–smoothed particle hydrodynamics (PD-SPH) coupling model for addressing FSI. A stable and efficient coupling algorithm for data transfer between PD and SPH is put forward. In this coupling strategy, a PD particle directly participates in solving the SPH governing equations when it is identified to be within the support domain of an SPH particle. This can be done since the SPH quantities including the density, velocity, and pressure of a PD particle are naturally attainable within the framework of non-ordinary state-based peridynamics theory. Concurrently, in solving PD governing equations, reaction forces from SPH particles act as external forces for PD particles, determined straightforwardly through Newton's third law. As such, the proposed PD-SPH coupling strategy is straightforward to implement and offers high computational efficiency. Validation examples demonstrate that the proposed PD-SPH coupling model is computationally robust and adept at capturing physical phenomena in diverse FSI scenarios involving breaking free surfaces of fluid and large structural deformations of solid. Moreover, the proposed PD-SPH coupling model is flexible introducing no constraint conditions for applications and can accommodate different particle resolutions for PD and SPH domains. These features enable a broad application range of the proposed PD-SPH coupling model including simulations of explosion-induced soil fragmentation, rock fracture, and concrete dam failure, which will be conducted by authors in the near future.