Sound radiation of cross-laminated timber panels based on a higher order plate theory

Abstract

In this contribution, the problem of sound radiation by a rectangular baffled cross-laminated timber (CLT) plate excited by a point force is addressed. Due to the inherent properties of CLT, a higher order shear deformable plate theory is needed to capture its deformation field. To this end, a recently proposed equivalent single layer plate theory is extended to incorporate dynamic effects. The derived plate model is applied to flexural wave propagation in infinitely extended plates, revealing coincidence frequency bands of the considered CLT elements. For a simply supported rectangular plate, natural frequencies and total acoustic power output to the far-field are computed. Throughout all simulations, results obtained by the proposed higher order plate theory are set in contrast with those applying first order shear deformation theory and classical laminated plate theory, because those models are typically used for vibro-acoustic simulations of cross-laminated timber panels. Comparison of the natural frequencies shows that these quantities of the higher order theory are in excellent agreement with the outcomes of finite element simulations based on continuum elements. In contrast, the outcomes of the lower order models deviate with increasing frequency. Consequently, both lower order models fail at assessing acoustic power output in the low to mid frequency range when comparing results with the proposed plate theory.