FILTER BANKS IMPLEMENTATION OF NUMERICAL MODELS FOR VIBROACOUSTIC ANALYSIS IN THE MEDIUM FREQUENCY RANGE

• Published in: Journal of sound and vibration 1998-05, Vol.213 (1), p.35-54
• Main Authors: Gorog, S., Micheau, P.
• Format: Article
• Language: English
• Subjects: Acoustics; Exact sciences and technology; Fundamental areas of phenomenology (including applications); Physics; Structural acoustics and vibration
• ISSN: 0022-460X; 1095-8568
• DOI: 10.1006/jsvi.1997.1425

A numerical method is proposed for predicting the vibroacoustic response of a viscoelastic structure submitted to harmonic forces in the medium frequency range. The structure is described as a finite dimension dynamical system. The frequency domain of interest is divided into several different subdomains. The method consists of solving a set of time domain equations of motion where each of them is associated with a given frequency subdomain. This time–frequency study is formulated within the framework of non-uniform modulated filter banks. Conditions are given to ensure that the analysis and the synthesis banks allow reconstruction of the complete investigated displacement field from time solutions. A low-pass filter with a compact time support is designed to ensure an efficient computation. To illustrate the discussion, two examples using different variational approaches are proposed. First, flexural vibrations of anin vacuosteel plate described by a finite element method is considered. Second, a semi-analytical method is used to describe a point loaded steel plate radiating in air.