Prediction of Acoustic Power Using Nodal Analysis: A Case Study on a Plate Treated with Constrained Layer Damping

摘要

This work examined the use of modal analysis and a point source acoustic model of plate to evaluate the noise control benefits from partial coverage damping. The results were presented here for the case of a bare plate and thirteen configurations of applied damping. A plate was mounted in heavy frame and vertically suspended in an anechoic chamber. The frame was driven by a shaker at the frequency of the plate's fourth mode. The acoustic power out in this configuration was evaluated using acoustic intensity methods. A modal analysis was done on the plate in each configuration. The velocity/force FRF (frequency response function) was determined between the modal analysis driving point and input point for the shaker. This information was used to develop a point source acoustic model for the plate. The results of the model were evaluated against the results of the intensity scans to judge its usefulness in rapidly determining the acoustic benefits of partial coverage damping configurations without acoustic measurement facilities.