Optimal Design of Vehicle Dash and Floor Sound Package Based on Statistical Energy Analysis 2015-01-0661

An increasing demand for vehicle noise control has been proposed and at the same time, vehicle weight and fuel economy have become critical for the automotive industry. The methodology of statistical energy analysis (SEA) is used to balance both light weight and high noise insulation performance. In this paper, the vehicle dash and floor sound package systems, which are two of the major paths for vehicle interior noise, are studied and optimized by CAE and testing technology. Two types of sound packages which are the conventional insulation system and the lightweight one are chosen for the vehicle dash and floor system. The vehicle dash and floor systems are modeled by SEA and the transmission loss (TL) of the dash and floor system is analyzed, respectively. Several influence factors of the TL are also analyzed, such as sound package coverage, the leaks, etc. The results of the TL analysis show that under certain sound package coverage or leaks, the TL of the dash and floor system with the conventional sound package is a little larger than the TL with the lightweight one. However, the lightweight sound package system has better absorption property and the advantage of weight reduction. Meanwhile, the full vehicle SEA model is built up and the noise transfer path is analyzed. By using the full vehicle noise reduction tests, the full vehicle SEA model and the main noise transfer paths are validated. Then, the vehicle exterior sound pressure levels (SPL) are tested under several load cases inside a semi-anechoic chamber. By applying the vehicle exterior SPLs to the full vehicle SEA model, the correlations are performed between the simulation and tests. Finally, the sound package systems of the dash and floor are analyzed and optimized by the full vehicle CAE and testing analysis.