Title: Identification of noise modes for automobile operational modal analysis

Authors: Zhang Shouyuan, Zhang Yimin, Li He, Wen Bangchun

Addresses: CAE Department, Nanjing Automobile Research and Development Center, No 128, Hongshan Road, Xuanwu District, Nanjing, Jiangsu 210028, P.R. China. ' School of Mechanical Engineering and Automation, Northeastern University, No 11, The Third Ally, Wenhua Road, Heping District, Shenyang, Liaoning 10004, P.R. China. ' School of Mechanical Engineering and Automation, Northeastern University, No 11, The Third Ally, Wenhua Road, Heping District, Shenyang, Liaoning 10004, P.R. China. ' School of Mechanical Engineering and Automation, Northeastern University, No 11, The Third Ally, Wenhua Road, Heping District, Shenyang, Liaoning 10004, P.R. China

Abstract: In rotating machinery, the input excitation does not meet the requirement of operational modal analysis (OMA). In this article, an effective and improved method of distinguishing forced harmonic response from measured vibration signal is presented based on the differences of the statistical properties of a stochastic signal and a harmonic signal. It makes the OMA applicable to the situation of existing periodic excitation. In order to prove the effectiveness of the proposed method, a modal experiment of a steel plate excited by a motor is performed. Then, an OMA is performed to solve the vehicle interior noise problem. Combining the projection channel technique with the advanced method, most noise modes, especially harmonic modes are successfully separated. Precise modal parameters of the car are obtained in typical working conditions which provide guidance of the dynamic modification and show that the harmonic identification method has great practical value.

Keywords: EFDD; enhanced frequency domain decomposition; harmonic mode; OMA; operational modal analysis; probability density function; vehicle noise; harmonic identification.

DOI: 10.1504/IJVNV.2008.024341

International Journal of Vehicle Noise and Vibration, 2008 Vol.4 No.4, pp.304 - 316

Published online: 01 Apr 2009 *

Full-text access for editors Full-text access for subscribers Purchase this article Comment on this article