Two modelling techniques for the vibration and transmission loss of a nonlinear vibro-acoustic system

Abstract

Fahy’s and Pretlove’s modelling techniques for a vibro-acoustic system have been employed in many research works. This is the first article addressing the differences between these modelling techniques for a nonlinear vibro-acoustic system. Pretlove’s technique is used for vibro-acoustic systems with one flexible panel only (or 2D enclosures); Fahy’s is applied to vibro-acoustic systems with multiple flexible panels (or 3D enclosures). The main difference between them is that all acoustic boundary conditions can be satisfied in the 2D modelling technique, while only rigid acoustic boundary conditions can be satisfied in the 3D modelling technique. The multi-level residue harmonic balance method, which was recently developed and modified from the classical harmonic balance method, is employed here. The advantage of this method is that it requires less computation effort when solving the nonlinear equations generated in the entire solution process. The comparisons between various transmission loss and nonlinear vibration results generated from the two models are investigated.