An improved SPH-FEM coupling approach for modeling fluid-structure interaction problems

An improved smooth particle hydrodynamics-finite element method (SPH-FEM) coupling approach was developed for investigating fluid-structure interaction (FSI) problems. To deal with the conjunction of physical quantities at the fluid-structure interfacial region, an interface particle coupling strategy was proposed, in which two kinds of virtual interface particles, i.e., interfacial repulsive particle and associated ghost particle, were arranged to accurately represent the reciprocal interactions between fluid and structure. What is more, a new density correction method combining the delta-SPH and Shepard filter was developed to obtain smoother pressure distribution and to improve numerical stability of SPH calculation. The accuracy and efficiency of the proposed approach were verified through analyzing two typical FSI problems, deformation of an elastic plate subjected to time-varying water pressure and fluid flow in a rolling tank interacting with an elastic beam, and comparing the simulation results with experimental observations and other previously published results. Finally, the proposed coupling approach was further employed to study the fluid sloshing in a motional tank and the influences of baffle in tank on sloshing. Numerical results demonstrate that the proposed improved SPH-FEM approach is applicable to several types of fluid-structure interaction problems with high accuracy and stability.