Speaker
Description
Existing numerical models reliably predict flanking sound transmission in cross-laminated timber (CLT) junctions when the stiffness of the connection approaches either the ideally rigid condition or that of an elastic layer interposed between plates. Nevertheless, it is still challenging to deterministically define coupling stiffness values for modelling the direct mechanical contact at the interface between plates. In this contribution, a numerical-experimental investigation is presented with the aim of highlighting fundamental issues for the determination of such coefficients. The vibration reduction index Kij was measured for two configurations of a CLT L-junction mock-up. In the first case, the plates were in direct contact and connected by angle brackets. In the second, they were left in contact with each other, but without any fasteners. The comparison of finite element method simulations against experiments highlighted that the plates' coupling stiffness conditions are influenced by the simultaneous action of both the connectors and the static load on the junction. This is consistent with findings from previous studies on the effects of junction loading on flanking sound transmission. Implications of this study include the necessity of deriving an explicit relationship between the constraint/load conditions of the junction and the coupling stiffness coefficients at the plates' interface.