Some effect of trim and body panels on the low-frequency interior noise in vehicles

Abstract

Structure borne noise dominates the interior noise in vehicles at low frequencies. One of the basic vinroacoustic characteristics of the trimmed body is the noise transfer function, i.e., the acoustic response at a selected position in the passenger compartment, e.g., driver’s ear due to a mechanical excitation at a selected body mount. Detailed CAE models based on the FE method are today available for calculating this characteristic at low frequencies, corresponding to the engine idling and road excitation. However, the accuracy of CAE predictions of interior noise is still considered insufficient for the so-called analytical sign off, i.e., zero-prototypes vision. The current paper describes some investigations into the contribution of individual body panels to the overall interior noise. Also, the effect of selected interior trim items on the area investigated. Relative errors of prediction at different trim levels and different frequency ranges are discussed. Both experimental and CAE results are provided. The aim is to better understand the way the interior noise in vehicles is created, and how it can be controlled.