Calculation of sound insulation of softwood samples at normal incidence and comparison with experimental data
The acoustic simulations were carried out for softwood and composites in order to evaluate their sound properties. Theoretical value of sound insulation was predicted by regarding the substances in the wood cell wall as equivalence to specific medium based on Biot model, and the wood microscopic characteristics, such as the length and diameter of tracheid, diameter of pit, and porosity, were taken into account for determining the equivalent density and bulk modulus of wood. By comparing the tested and predicted values of sound insulation, the conclusions were drawn as follows: the predicted values of sound insulation were significantly correlated with the tested values for wood and wood composites. As for Masson pine, the adjacent of earlywood and latewood was considered as sandwich structure for the calculation of sound insulation. The transfer function involved in sound insulation simulation provided an effective method to characterize the sound insulation volume of wood and wood composite in construction and decoration areas.