ABA - New Generation of Vehicle Dashmats 2005-01-2277

Automotive engineering is taking a deeper look at the role of NVH engineering and design. Controlling the vehicle sound is one of the musts in designing successful automobiles today. While the focus is usually on powertrain noise, this report covers the concept of a new technology of dashmats. This new generation of dashmat is constructed of an absorptive layer, a barrier, and another absorptive layer (ABA). Typically, dashmats are placed inside the vehicle on the firewall between the powertrain and the driver. This dashmat blocks and absorbs powertrain noise as well as the vehicle background noise heard at the driver's ear. This report focuses on two types of competing dashmats-the light weight absorptive dashmat which acts by absorbing the sound rather than blocking it and the new generation of vehicle dashmat (ABA) which performs by blocking and absorbing the powertrain noise as well as the vehicle background noise. Analytical statistical energy analysis was utilized to understand and compare the NVH performance and weight of both dashmat technologies. The data revealed that the ABA dashmat has superior performance over the light weight dashmat technology due to its noise blocking and absorbing capability. Besides of this advantage, the ABA dashmat tested was comparable in weight to the absorptive dashmat. As a part of this study, plaque and vehicle firewall subsystem testing was studied and a full vehicle evaluation was conducted on a chassis dynamometer along with using a point acoustic simulator.