| The rear axle is the one of the main vibration and noise resources in transmitting mechanism. According to previous studies, the noise stem from the impact on axle housing which is produced by the gears joggling. Moreover, the rear axle is sustained by suspension in the vehicle, which will absolutely lead to the rear axle's flexural vibration. Especially, when resonance vibration happens, the SPL of noise appears extremely high, destructing mechanism reliability seriously and making passenger uncomfortable.It makes full use of FEM and BEM technology in this paper to analyze the noise and vibration of axle, which provides reasonable suggestion in coping with the NVH issue of the rear axle. The main jobs of this paper are as follow:Firstly, the 3D model and FE model of the rear axle were established under CATIA and HYPERMESH platform respectively, which is the basic step for the next analysis. Secondly, the constraint modal analysis of the rear axle housing was carried out in order to attain the natural frequency and vibration shape of the rear axle housing within 2000Hz. It shows that the 1st natural frequency is 288Hz, which is much higher than road disturbance frequency. Thirdly, with the accurate gear models and assembled relationship, the transient response was measured to get vibration time-domain data of the nodes on the exterior surface of axletrees and frequency-domain data was obtained by means of taking advantage of FFT technology. Then, the frequency and noise analysis was carried out which focused on the frequency where was supposed to produce higher vibration and noise According to constraint modal and transient response analysis ,the results indicated that the main noise radiation resources are the axle's rear cover, The method to reduce the noise is to reduce the vibration of axle.Finally, the main noise radiation resources of the rear axle was modified by means of adding groove shank to axle's rear cover ,which turn out to be good effect.
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