Abstract Summary
Wide attention and research have been focused on the vibration control of thin wall structures immersed in fluid environment, for which fuel containers, vessel shells and underwater robotics are among the most frequent examples. Designing such structures with respect to the desired vibration property increasingly requires application of microstructured plates and shells. In this work, we propose a finite element framework that allows predicting vibration behaviours for composite plates with periodic microstructures in the context of fluid-structure interaction (FSI). In this regard, inertial effects of the fluid are taken into account by considering a fluid induced added mass, which we calculate based on one or both sides of the composite plate. We then perform vibration analysis by prescribing Bloch boundary conditions to the periodic unit cell, which we model using a Mindlin plate finite element that integrates the FSI effect. We validate the numerical framework by considering a fluid-structure coupled system, composed of a periodic composite plate which is fixed to a number of fluid cavities filled with ideal fluid. Based on this configuration, we investigate the influence on the plate vibration due to the fluid properties which include the fluid density, the number and size of the fluid cavities. Simulations revealed that the first two parameters present significant effect on the structure vibration since both the band gap range and position can be controlled by using different fluid densities and numbers of cavities. Meanwhile, we confirmed negligible impact on the vibration mode shape due to FSI since its effect mainly remains on the inertial mass of the structure. To confirm the effectiveness of our band gap predictions, we further performed dynamic response simulations in the frequency domain and considered extra cases of microstructure design. Comparison between the band gap calculation and frequency response analysis based on the considered cases validates the accuracy and adaptability of the proposed numerical approach, which can be used to assist the microstructure design of composite plates with FSI for specified vibration behaviours.
