The acoustic polar scan: a novel sonic probe for the characterization of lightweight wood panels

Lightweight wooden panels such as Cross Laminated Timber (CLT) offer an alternative to concrete or masonry walls, as they present an economical solution with several advantages such as easy and fast assembly and good fire resistance. On the downside, the compilation of individual beams in different directions gives rise to CLT panels with an increased complexity in mechanical properties, whereas the low mass results in poor acoustical isolation between rooms. Moreover, due to the combination of wood and glue, the visco-elastic parameters of these panels are very hard to model, which makes the design of constructions with proper characteristics, both structural and acoustical, a difficult matter. The goal of this project is to develop an Acoustic Polar Scan (APS) method that can be employed for the anisotropic mechanical parameter inversion and acoustical isolation characterization of lightweight wood panels in construction engineering. The APS design and methodology involves a motorized multiple angle of incidence plane wave excitation using a parametric antenna, data acquisition using laser Doppler vibrometry, and a multi-parameter visco-elastic tensor inversion analysis of the data. Experiments on real CLT construction elements will be conducted to validate and optimize the methodology and the set-up. The ultimate goal is to reach a deep theoretical understanding of the mechanical and dynamical behavior of CLT that would permit the optimization of desired design properties.