Coupling of a Nonlinear Structure with Sloshing

In this paper the role of solid nonlinearity on the fluid–structure interaction (FSI) is studied. First a simple mass-spring-damper system with a third-degree spring is coupled with a linear sloshing system to study the effect of solid nonlinearity. It shows that even both systems show similar behavior in free vibration tests, but nonlinearity caused 50% less on the amplitude of vibration. Then a higher order solid system coupled with a sloshing tuned liquid damper which is modeled by boundary element method (BEM) is examined. Finally, the coupling of a nonlinear solid with the sloshing system calculated at high-resolution method of smoothed particle is analyzed. The results reveal that considering surface nonlinearity in BEM has not improved the prediction significantly and the full NavierStokes calculations is in another phase and amplitude to a step response of the system even after two periods of the system in comparison with linear estimation. As shown the nonlinearity in solid part can cause a big difference in response of coupled system that pointed the necessity of the use of accurate fluid models such as BEM or smoothed particle hydrodynamics method as well as solid system identification before the coupling.