Measurement and prediction of flanking transmissions in wooden CLT constructions using Reverse-SEA

For lightweight constructions, prediction of Flanking Transmission is a difficult issue. Wooden structures are orthotropic and there are multiple possibilities to compose and design junctions. A model is proposed in standard EN 12354-serie, it uses junction characteristics to be measured. In this article authors show measurements results performed on multistory buildings erected during 2016. Measurement results used are generated from 2 Cross Laminated Timber (CLT) Buildings. The modelling strategy to predict such structures is detailed. The framework of the methodology is Statistical Energy Analysis (SEA). SEA involves cutting the structure into subsystems and decomposing the spectrum into third-octaves or octaves. In this way, the exchange of energy flow in the substructures can be analysed. The parameters that govern vibrational transmission between subsystems are damping and coupling loss factors and can be identified experimentally by reversing the problem. The approach is, first, based on sub-structuring strategy of structure; second, on experimentally measured coupling and damping loss factors; third, on extracting vibration level difference to estimate one by one all flanking passes. All results were generated during “Acoudeum” project financed by INEF4 - ANR platform.