关键词: 振动与波, 制动抖动, DTV, 频次分析, 衬套刚度, 悬架模态

Abstract:

In order to study the influence of Disc Thickness Variation (DTV) and bushing stiffness of suspension on brake judder, in this paper, the time-frequency characteristics of brake judder were studied through vehicle road test. The frequency analysis of DTV data was carried out based on FFT, while the suspension modes were calculated using multi-body dynamics program. The results show that the spectrum of vibration acceleration under vehicle road test has order feature. The DTV data mainly consists of the first-order and second-order harmonic components, which is consistent with the phenomenon that the first two orders of tire rotational speed are the main contributions of brake judder, it is helpful to improve brake judder by decreased amplitude of harmonic components. The longitudinal mode is the reason of brake vibration is strongly excited, the higher bushing stiffness of low control arm, the bigger suspension modal eigenvalue and the lighter brake judder. Therefore, brake judder can be reduced if the stiffness of bushings are reasonably calibrated.