A coupled alpha-FEM for dynamic analyses of 2D fluid‐solid interaction problems

An alpha finite element method using triangular elements ( $\alpha$ FEM‐T3) which combines the node‐based smoothed FEM (NS‐FEM‐T3) and standard FEM‐T3 with a scale factor $\alpha \in [0,1]$ is extended to the dynamic analysis of 2D fluid–solid interaction problems based on the pressure–displacement formulation. The gradient smoothing technique based on a part of the smoothing domains associated with the nodes of the triangles is used to smooth both the gradient of pressure and gradient of displacement. This gradient smoothing technique can provide proper softening effect and thus improve significantly the accuracy of solution of coupled system. Some numerical examples have been presented to illustrate the effectiveness and stability of the $\alpha$ FEM‐T3 ( $\alpha =0.6$ ) compared with some existing methods for 2D fluid–solid interaction problems.