Structural Borne Noise Control in Passenger Cars and Light Commercial Vehicles (LCV) Utilizing New Light Weight Damping Systems

摘要

Light weighting vehicle acoustic components and improving the performance level of sound abatement treatments is becoming more important to automotive manufacturers due to increased fuel economy requirements established by the Corporate Average Fuel Economy - (CAFE) standards [1], and the consumer’s demand for ever improving sound quality inside the vehicle cabin. In tests conducted by Ricardo Inc. for the Aluminum Association Inc., a 2008 report estimates that for every 45 kg of mass removed from passenger vehicles and light weight commercial vehicles (LCV) up to a 1 percent increase in fuel mileage can be achieved [2]. Automotive OEM’s expect that sound abatement products, sound barriers, absorbers, and damping materials contribute to this reduction in vehicle weight.Through the use of new light weight technologies with densities between 0.4 gm/cm3 and 0.7 gm/cm3 it is now possible to achieve mass reductions over traditional extensional layer and constrained layer materials by as much as 60% and reductions over liquid applied spray dampers (LASD) of 30% while maintaining, and in some cases improving, the damping level and transmission loss performance of these materials improving the sound quality within the vehicle cabin. Utilizing established test methodology for measuring the vibration damping properties of materials [3] and for evaluating the transmission loss properties of materials [4], this paper highlights the capabilities of this new light weight technology for reducing mass and for handling structure borne noise versus traditional extensional layer and constrained layer materials.