Analysis And Control On The Rumble Noise Of A SUV

In recent years,with the vigorous promotion of new energy vehicles on the global scale,the ratio of tire / road noise in the whole vehicle noise is getting higher and higher,so the tire / road noise is gradually paid attention to by major automobile factories.Rumble noise belongs to low frequency structural noise and it can easily lead to the passengers’ discomfort,influencing the riding comfort.Therefore,more and more vehicle plants’ NVH departments are focusing on the rumble noise.This article is based on the promotion project of the rumble noise and the noise reduction control of the rumble noise pressure peak at 37 Hz is carried out by the method of combining simulation and experiment.The main contents are as follows.The mechanism of rumble noise was analyzed.The excitation source,the transmission path and response system were found.According to the engineering practice,it was decided to optimize the structure of the body mainly.The finite element model of the body system was established.The natural frequencies and modes of the first six steps to the body in white were obtained by simulation analysis.Compared with the results of experimental modal analysis,it was proved that the finite element model was accurate which laid the foundation for the subsequent contribution analysis of the body plate.Based on the finite element model of the body in white,the finite element model of the TB body was built.The acoustic modal analysis was done and the acoustic solid coupling model of the body system was established in the software of ANSA and LMS virtual.lab.The curve of the body noise transfer function was obtained by using the unit white noise excitation.Compared with the noise pressure curve of the interior rumble,the result of the contribution analysis was output.The real vehicle vibration sound transfer function was test when the hardness of backdoor stopper block was different.Its optimum hardness was explored.Based on the modal analysis of the backdoor in original support and the modal parameters,a reasonable dynamic vibration absorber was designed.Through the real vehicle verification,the effect of noise reduction is good.