A novel fluid–solid interaction framework by coupling three dimensional explicit discontinuous deformation analysis and material point method

Abstract

Fluid-solid interactions (FSI) are ubiquitous in natural processes and engineering fields. Although numerous attempts have been made to describe the FSI, it still remains a significant challenge to accurately capture the complex dynamic interaction between fluids and arbitrarily shaped solids. In this study, a novel FSI framework is proposed by coupling three dimensional (3D) explicit discontinuous deformation analysis (DDA) and material point method (MPM). DDA demonstrates superior capability in handing solids with arbitrary shape, while MPM exhibits distinct advantages in capturing free surface flow. The contact detection algorithm between DDA blocks and MPM particles are presented in detail. Normal interaction force is calculated by penalty function method, while tangential interaction force is determined by momentum exchanges. Several benchmarks, including water entry test of a single sphere, underwater landslide, and Scott Russell’s wave generation are adopted to validate the effectiveness of the proposed hybrid method. Finally, the impact force of dam break flow on downstream structures is investigated, and the fitting formulas relating impact force to structural height and distance to dam are obtained. The entire process of wedge landslide induced surge is also simulated, and the landslide movement characteristics, surge propagation, and energy evolution mechanisms are discussed comprehensively. These classic disaster simulations demonstrate the immense potential and feasibility of the 3D DDA-MPM method for addressing complex FSI problems in geotechnical engineering.