Reproduction of the vibroacoustic response of panels under stochastic excitations using the source scanning technique

Abstract

The reproduction of the vibration and acoustic responses of structures under random excitation such as the diffuse acoustic field or the turbulent boundary layer is of particular interest to researchers and the transportation industry (automobile, aeronautics, etc.). In practice, the characterization of structures under random excitations requires making in-situ measurements or using test facilities such as the wind tunnel, which are complex and costly methods. Based on the previous considerations, the necessity of finding simple, cost-efficient and reproducible alternative methods becomes obvious. The source scanning technique based on a single acoustic source and the synthetic array principle is one of these alternative techniques. The present paper proposes to assess its validity by comparing its results with numerical and experimental ones. An academic case study consisting of a baffled and simply supported aluminum panel under diffuse acoustic field and turbulent boundary layer excitations is considered. The experimental vibration response of the panel as well as the transmission loss using the proposed process are compared to results from random vibration theory on one hand. On the other hand, the same experimental results obtained using the source scanning technique are compared with results obtained with measurements using a reverberant room (diffuse acoustic field) and an anechoic wind tunnel (turbulent boundary layer). These comparisons show good agreement that validate the source scanning technique for the considered panel.