基于结构阻尼的悬挂冲击噪声诊断

Impact Noise Diagnosis of Suspension Systems Based on Structural Damping

汽车悬挂受到路面冲击而产生振动,易导致主要工作部件损坏,故障点难以诊断定位。为此,提出通过采用冲击噪声识别悬挂部件结构阻尼来确定故障部位。首先建立反向积分作为振声脉冲响应信号处理的理论基础。反向积分法具有明确的物理意义,仿真和实验验证其能够有效识别单自由度阻尼比和带宽范围内的损耗因子。然后对比分析减振器与稳定杆球头的冲击噪声信号在时域、包络线、频谱和反向积分曲线上的差异,并寻找特征参数。结果表明,两者反向积分曲线的对数衰减率存在显著且稳定的差异,该参数可作为悬挂系统冲击噪声的量化诊断参数。

The suspension system transmits the impact of the road surface to the body of the car.It is difficult to diagnose the abnormal noise of the suspension components.Therefore,a new fault diagnosis method is proposed in which the fault location is identified by the structural damping.Firstly,the theoretical basis of inverse-time integral is established and applied to structural damping identification,which is later verified by simulation and experiment.The inverse-time integral has a definite physical meaning and can effectively identify the single-DOF damping ratio and loss factor in the bandwidth area.Then the time domain,envelope,spectrum and inversed-time integral curves of the impulse sound signal of the shock absorber and the ball-head of the stabilizer bar are compared and analyzed.And the characteristic parameters are found.The results show that there is a significant and stable difference of the logarithmic attenuation rate between the two reversed-time integral curves,and this parameter of the difference can be used as the diagnostic parameter of the impact noise of the suspension.