Caracterização experimental e modelagem do comportamento vibratório de estruturas submersas

Abstract

This work investigates the procedures for experimental finite element-based numerical characterization of submersed structures. Based on the hypothesis that the fluid remains in steady condition, numerical simulations are performed aiming at obtaining the time harmonic and time responses of two types of structures, namely beams and rectangular plates completely submersed. In parallel, experimental tests based on impact excitation are carriedout in laboratory and the two sets of dynamic responses are compared. Aiming at improving the predictive capacity of the finite element models developed, both without fluid interaction and in the immersed condition, a procedure for adjustment based on the minimization of the differences between numerical and experimental eigensolutions is implemented. The results obtained enable to characterize the influence of the fluid on the dynamic structural behavior and, specifically, the damping increase and the effect of added mass. It is also shown that the model adjustment procedure provides effective improvement of the predictive capacity of the finite element models implemented.