An efficient selective cell-based smoothed finite element approach to fluid-structure interaction

This paper describes an efficient and simple selective cell-based smoothed finite element method (CS-FEM) for partitioned fluid-structure interaction. Depending on a fractional-step fluid solver, a selective smoothed integration scheme is proposed for the Navier-Stokes equations in stationary and deforming domains. A simple hourglass stabilization is then introduced into the under-integrated smoothed Galerkin weak form of the fractional-step algorithm. As a result, the computational efficiency is considerably boosted in comparison with existing CS-FEM formulation. Meanwhile, the CS-FEM is applied to spatially discretize the elastodynamics equations of nonlinear solids as usual. After discussing the mesh moving strategy, the gradient smoothing is performed in each individual interface element to evaluate the fluid forces acting on oscillating rigid and flexible bodies. The block Gauss-Seidel procedure is employed to couple all interacting fields under the arbitrary Lagrangian-Eulerian description. Several numerical examples are presented to demonstrate the desirable efficiency and accuracy of the proposed methodology.