Replacement of damping pads by using soft visco-elastic foam while maintaining high insulation properties

摘要

This article presents the development procedure of new innovative visco-elastic foam with alow Young’s modulus as well as a high loss factor. Due to this high loss factor, thestructure-borne noise is reduced in comparison with elastic foams, while achieving acomparable level of structure-borne and airborne Insertion Loss. Therefore, with this newfoam system a significant weight reduction is achieved by removing damping pads thanksto this new visco-elastic foam. The development and validation of this new visco-elasticfoam is based on measurements and Finite Element Method (FEM) simulations withairborne and structure-borne excitations and takes into account both the reduction ofstructure-borne noise due to the damping interaction of the structure with the poro-elastictrim, as well as the radiation of sound. Poro-elastic Finite Element Method simulationshave been carried out in combination with statistical tool post-treatments, like the “Designof Experiments” method, in order to identify the significant design parameters of theoptimized visco-elastic foam. The validation of this new visco-elastic foam has been carriedout on flat samples first and then at component level on a complete floor module. Finally,measurements at vehicle level have validated the efficiency of this new lightweight acoustictreatment strategy.