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In this paper, a lightweight automotive prototype using alternative materials and gauge thickness was studied using numerical method. NVH performance was the main target to be verified in this study. The frequency response function (FRF) analysis of inner sound pressure was performed by associating FEM (finite element method) with BEM (boundary element method). Detailedly, in order to get the dynamic behavior of the auto-body structure, a frequency response function (FRF) of the body structure was calculated from 1Hz to 150Hz using FEM. Afterwards, the pressure response of the interior acoustic domain was solved by BEM. In order to reveal the structural panels that contributed most significantly to the interior sound pressure, the panel acoustic contribution analysis (PACA) was performed. Finally, the most contributing panel was located. The method used here was timesaving and helpful for the following structure optimization.

Excessive wind noise is one of the most complained problems by owners of new vehicles as evidenced by JD Power Initial Quality Study (IQS) in recent years. After the vehicle speed surpasses 100 km/h, wind noise is gradually becoming the dominant noise source. In an effort to reduce aeroacoustic noise level, Beamforming (BF) is a very effective noise source identification technique used during vehicle wind noise development phases. In this work, based on the planar BF methodology, a large semi-circle microphone array is designed in accordance with the desired resolution and dynamic range pertaining to actual noise source distribution on a typical passenger vehicle. Acoustic array calibration and mapping deformation correction are accomplished by multi-point source method, and the Doppler Effect due to wind is corrected by the location calibration method.