Hydroelastic natural vibrations of perforated plates with cracks

This paper deals with the modal analysis of the clamped-edge circular perforated plates with ligament penetrated cracks both in air and submerged in fluid. The effect of the cracks to natural frequencies and modal strain energy of a perforated plate with ligament fractured cracks is studied by finite element analysis. The numerical results indicate that the cracks have clear effect on dynamic characteristics of a perforated plate. The simulation shows that the caused variation of modal strain energy is more sensitive than natural frequencies changes in the presence of growing cracks. The presence of fluid significantly influences the dynamic behavior of a perforated plate. Cracks also affect the fluid pressure distribution at the fluid-plate interface. The power flow based technique related to strain energy and its potential development into a strong tool in practical health monitoring are discussed.