Browse Publications Technical Papers 2009-01-2202
2009-05-19

Effect of Damping on Sound Transmission Loss through Automotive Body Panels 2009-01-2202

In this paper, sound transmission characteristics of typical stamped steel automotive body panels are investigated. In particular, focus was placed on the dash panel since it separates the interior space from the engine. Three dash panels were considered with the same geometry but different damping characteristics. These dash panels included a bare steel dash, a bare steel dash with a Patch Constrained Layer (PCL) and a laminated steel dash. Sound transmission loss was measured in a transmission loss suite. It was observed that the measured transmission loss of the laminated steel dash was significantly higher than the other dash panels throughout the mid and high frequency regions. A hybrid approach using both Finite Element Analysis and Statistical Energy Analysis (SEA) was used to predict and correlate the sound transmission loss for these panels. The geometry effects of the dash panels were considered while calculating SEA parameters. Coupling loss factors between the dash panel and acoustic cavity were predicted considering the effects of increased stiffness and the impedance mismatches due to discontinuities along the surface of the dash. The power contributions to the receiving cavity by resonant paths and non-resonant paths were investigated. It was observed that the resonant power contribution was significantly lower for the laminated steel dash as compared to the other dash panels. This resulted in higher transmission loss for laminated steel dash compared to the transmission loss for other two panels.

SAE MOBILUS

Subscribers can view annotate, and download all of SAE's content. Learn More »

Access SAE MOBILUS »

Members save up to 43% off list price.
Login to see discount.
Special Offer: With TechSelect, you decide what SAE Technical Papers you need, when you need them, and how much you want to pay.
X