A modified immersed smoothed FEM with local field reconstruction for fluid–structure interactions

Abstract A modified immersed smoothed finite element method (mIS-FEM) is proposed for fluid–structure interactions (FSI) using linear triangular elements in this paper. A sharp interface treatment is proposed and implemented to modify the original IS-FEM. The proposed treatment reconstructs the fluid velocity field near interface using auxiliary triangles, leading to better resolutions without much extra efforts. In the proposed method, the fluid solver is the FEM with a semi-implicit characteristic-based split (CBS) scheme using linear triangles. For the solid solver, the S-FEM based on explicit total Lagrangian formulation is used to solve finite solid deformation. Several numerical examples are employed to verify proposed mIS-FEM, and to examine the improvements. The results demonstrate that mIS-FEM is a reliable and robust numeric method for interactions between fluid and solids undergo large deformation.