Characterisation of the equivalent orthotropic elastic properties of CLT panels

Cross-laminated timber (CLT) panels are non-homogenous and non-isotropic structures, whose elastic properties are not easy to determine. The elastic, stiffness and structural resistance properties of a CLT panel can be experimentally determined using different approaches. In this study, the elastic properties of equivalent homogeneous orthotropic elastic panels, representing CLT elements with different layup configurations, are evaluated through static finite element (FE) simulations, based on the representative volume element (RVE) approach. This analysis allows investigating the influence of the number of layers, or the ratio of their thickness on the elastic behaviour of the panel. Moreover, this study aims to verify the suitability of static elastic properties of the equivalent orthotropic element in vibroacoustic analysis. The comparison of the numerically computed dispersion curves, of different propagation modes, evaluated both for the layered structures and the associated equivalent orthotropic elements showed that equivalent static elastic properties while providing a good approximation at the lowest frequencies, do not guarantee a good accuracy within the entire frequency range. Finally, the transmission loss numerically computed from layered and homogenised models of the CLT panels are also computed.