Abstract
The acoustic performance of complex periodic structures is of paramount importance in sustainable constructions. Nevertheless, traditional numerical methodologies like progressive impedance models, double-leaf theory or standard methodologies cannot offer reliable results, comparable to measurements. Even complete modelling using Finite Element (FE) simulations may not provide good results, due to the calculation of many variables and the consequent error propagation. For these reasons, in this paper an extensive investigation of numerical approaches accuracy is proposed and applied to complex periodic timber structures.
Transfer Matrix Modelling (TMM) method and simplified Finite Element simulations were used and compared to traditional methodologies. In order to obtain reliable results, a complete material and building element characterization is carried out.
Both transmission loss and radiation efficiency were computed in order to understand advantages and limitations of all these methods. Results clearly show that Transfer Matrix Method combined to simplified Finite Element analysis is the best method as regards to accuracy of results and that is able to correctly compute these two parameters as a function of frequency.