Radiation Efficiencies of a Submerged, Unbaffled Flat Plate: Numerical andPhysical Experiments

摘要

This thesis presents a method for predicting the radiated sound power ofstructures that combines numerical models of structural finite element and acoustic boundary element analyses. This method involves the generation and validation of a finite element model of an unbaffled, rectangular, flat plate through the use of material properties determined by matching numerical and experimental results and experimentally determined forced response characteristics such as modal frequencies, geometry, damping and generalized force. The finite element model is shown to represent accurately the mode shapes and resonance frequencies of the actual plate. Once a match was achieved between the forced vibration response of the numerical and physical models, the one third octave radiation efficiencies of the finite element model were calculated by means of a lumped acoustic parameter method and compared to experimental measurements conducted in a large water tank. The results of these comparisons show that this approach is capable of predicting the acoustic characteristics of the unbaffled, rectangular plate well.