Coupling Acoustics to Nonlinear Structural Models: Predictions and Experiments

Abstract

Coupled dynamic response has been observed for panels tested in an acoustic facility. The structural response of the panel interacts with the dynamics of the facility. At high test levels, the structural response will also be nonlinear. Response prediction requires time integration of nonlinear structural models. In the past decade, methods have been developed where a nonlinear finite element model of the structure is reduced to a low-order system of nonlinear equations to better enable the computations. In a previous study, a panel was subjected to loading in a progressive wave acoustic facility. Model predictions were made using the nonlinear structural reduced-order models. Poor agreement between the predictions and the experimental results suggested coupling between the structure and the acoustics of the facility. In a companion to this paper, an approach is proposed to couple acoustic modal models to the nonlinear structural reduced-order models. In this paper, the coupled approach is used to predict the experimental results. The coupled structuralacoustic model is now able to capture the salient features of the structural response, indicating that the acoustics of the progressive wave facility greatly influence the structural response of the panel.