Nonlinear FSI Due to Underwater Explosions

Abstract

A method of solution for the transient response of nonlinear fluid‐structure systems is presented. Finite element discretization is applied to the nonlinear hydrodynamic equations describing water. Performance of five equations of state describing water in the presence of strong shocks are compared for the case of shocks propagating underwater and reflecting from a rigid wall. Differences in the ratios of reflected to incident pressure indicate the need for correlation with experimental data. Results also differ from those obtained by using an acoustic (linear) fluid model. The dynamic response of a one‐dimensional water‐linear structure system is obtained for shock wave loading. The tendency of the fluid to damp the structural response is illustrated and shown to be greatly dependent on the structural stiffness. Analysis of a one‐dimensional water‐nonlinear structure system is performed to investigate dynamic limit point buckling.