Experimental Method for Extracting Dominant Suspension Mode Shapes Coupled with Automotive Interior Acoustic Mode Shapes 2014-01-2045

A finite element (FE) model of vibro-acoustic coupling analysis, such as a vehicle noise and vibration, is utilized for the improvement of the performance in the vehicle development phase. However, the accuracy of the analysis is not enough for substituting a prototype phase with a digital phase in the product development phases. Therefore, conducting the experiments with the prototype vehicle or the existed production vehicle is still very important for the performance evaluation and the model validation.

The vehicle noise transfer function of the road noise performance cannot be evaluated with the existed excitation equipment, such as the 3 or 6 directional electromagnetic shaker. Therefore, this paper proposes new experimental method to measure the road noise vehicle transfer function. This method is based on the reciprocity between the tire contact patch and the driver's ear location. The reaction force sensor of the tire contact patch is newly developed for the reciprocal loud speaker excitation at the passenger ear location. In addition, with this equipment, it is possible to extract the dominant structural mode shapes creating high sound pressure in the automotive interior acoustic field. This method is experimental structure mode participation to the noise of the acoustic field in the vibro-acoustic coupling analysis. This information is very important to improve the FE model accuracy to represent the physical phenomenon. The validity of the presented method is confirmed by the effectiveness of the structural countermeasures acquired by analyzing the structural causes from the extracted modes.