A coupled δ+-SPH-NOSB-PD method: Towards fluid-structure interaction problems involving violent free-surface flows and isotropic structural linear elastic deformations and failures

Abstract

In this paper, a robust integrated particle model is developed by coupling smoothed particle hydrodynamics (SPH) and peridynamics (PD) to deal with the fluid-structure interaction (FSI) problems involving violent free-surface flows and isotropic structural linear elastic deformations and failures. The partitioned approach is conducted in between a stable and accurate ${\delta }^{+}$-SPH fluid model and a non-ordinary state-based PD (NOSB-PD) structure model based on the idea of non-local interactions. The SPH fluid model is strengthened with a set of previously advanced numerical techniques, hence, the developed coupled scheme is referred to as an enhancement of the traditional SPH-PD. Crack initiation and propagation in structural responses under fluid dynamics are considered, which is relatively rare in previous FSI simulations. The information between the boundaries is transferred via the acceleration-based way and pressure integration method, which helps to ensure numerical stability and accuracy. In addition, a modified sequential staggered (MSS) algorithm is adopted to improve the efficiency when the time step of the structure significantly differs from that of the fluid. Firstly, the performance of the PD-based structure model is verified by three benchmarks, namely a free oscillating cantilever plate, stress distribution inside an isotropic plate with a circular opening and the Kalthoff-Winkler impact test. Then, several challenging FSI problems are simulated to validate the accuracy and robustness of the present FSI solver in predicting the fluid fields and the elastic response and fracture of the structure. The results achieved are in good agreement with the references, verifying the scheme's feasibility in this work.