Finite element acoustic analysis of a steel stud based double-leaf wall

Optimum acoustic performance of building components is a fundamental factor towards sustainable building design. Accordingly, it is essential that designers have the capability to effectively predict the acoustic performance to achieve sustainable designs. This paper introduces a 2-D Harmonic Acoustic Finite Element Analysis to predict the sound insulation of stud based double-leaf walls. This research was motivated by the necessity to develop acoustically efficient light weight building structures, which are both affordable and sustainable. Prediction of the Sound Reduction Index (R) of plasterboard partitions with structural links is a challenging problem due to the fluid-structure interaction (FSI) between the structural and fluid systems. Several finite element models to predict the sound reduction index of double-leaf walls were developed in compliance with BSENISO 717 and 140. The validity of the finite element predictions were assessed by comparison with experimental test results carried out in a certified laboratory. The effect of using different mesh sizes, fixing mechanisms and sound source locations on the predicted sound reduction index were looked into. The effects of air humidity and temperature on the experimental measurements of R values were also investigated. The FEA model presented in this work is capable of predicting the weighted sound reduction index (Rw) along with A-weighted pink noise (C) and A-weighted urban noise (Ctr) to within an accuracy of ±1 dB. Furthermore, the finite element modelling procedure reported can be extended to efficiently predict the acoustic behaviour of other building components undergoing FSI.