基于制动器多点接触模型的初始SRO和DTV对制动抖动的影响分析

Influence of initial SRO and DTV on brake judder based on disc brake model with multi-point contact

针对盘式制动器系统,假设制动盘与制动块存在多点接触,利用制动副摩擦系数—相对速度半经验理论模型,建立了制动器多点接触动力学模型,并通过台架试验验证了该模型的有效性。基于此模型,假设初始制动盘厚薄差和制动盘端面跳动具有正弦曲线特征,以制动力矩波动、制动压力波动的时频特性及均方根为评价指标,详细讨论了制动盘厚薄差和制动盘端面跳动的阶次、最大值及相位对制动抖动的影响。研究结果表明,制动盘DTV在圆周内的阶次特征决定了制动压力波动和制动力矩波动频率与转速的阶次关系;制动压力波动对制动盘SRO敏感性较强,制动力矩波动对制动盘DTV敏感性较强,制动压力波动均方根和制动力矩均方根与制动盘SRO和DTV最大值具有线性递增的关系;制动盘端面跳动的相位差通过改变制动盘厚薄差的最大值对制动压力波动和制动力矩波动产生影响。

For a disc brake system,the couples of brake disc and brake pads were supposed to be multi-point contact,and the brake dynamic model with multi-point contact was established considering a semi-empirical theoretical model of a friction coefficient-relative speed curve,which was verified by the rig experiment.Based on the model,assuming that the initial DTV and SRO could be represented mathematically as sinusoidal functions,the influence of the order,the maximum value and the phase of the initial DTV and SRO on brake judder were discussed in detail using the evaluation indicators of the time-frequency characteristics and the root mean square of the BPV and BTV.The results showed that the order of the DTV produces the order for the frequency of the BPV and BTV versus the angular velocity;the BPV has the stronger sensitivity to the SRO and the BTV has the stronger sensitivity to the DTV;the roots mean square of the BPV and BTV have linear incremental relations to the maximum values of the SRO and DTV;the phase of the SRO influences the BPV and BTV by changing the maximum value of the DTV.