Investigating acoustics and wave behaviour in cross-laminated timber panels

Abstract

Cross-laminated timber (CLT) is a timber product that is becoming increasingly popular in construction in NZ because of the ability to prefabricate panels off-site, as well as being lightweight and sustainable compared to other building materials. There is currently a lack of information on its acoustical properties, as the complex geometry through the thickness means it is difficult to model and predict sound transmission. The WFE (wave and finite element) method has been employed as it allows for a small segment of a material to be modelled using standard FE methods and can incorporate several material layers. It then requires finding the mass and stiffness matrices of the segment and post-processing them to determine the wave behaviour of the structure as a whole. The WFE method was used to model the sound transmission of several different CLT panels and these results were compared against measurements taken by the National Research Council Canada. In-house testing was also performed to obtain experimental wavenumbers, and these were also compared to wavenumbers produced by the WFE method.

Application of the wave and finite element method to predict the acoustic performance of double-leaf cross-laminated timber panels

“…6 A significant advantage of using the WFE method is that it can be applied to straightforwardly calculate the sound transmission loss of panels with arbitrary complexity through the thickness. The WFE method has previously been used to investigate the vibroacoustic characteristics of single-leaf CLT panels, 7,8 with the results comparing favourably to experimental measurements. The WFE method has also been extended to analyse the sound transmission of multi-layered panels with intermediate fluid layers by Yang et al 9 This method models the acoustic propagation within each fluid layer analytically.…”