含不确定参数的盘式制动器稳定性分析

STABILITY ANALYSIS OF DISC BRAKE SYSTEMS WITH UNCERTAINTY PARAMETERS

针对汽车盘式制动器的制动降噪问题,结合响应面法、复特征值分析法与可靠性分析方法,提出一种含随机模糊混合不确定参数的盘式制动器稳定性分析方法。该方法针对含随机和模糊参数的盘式制动器,建立其不稳定阶次模态的复特征值阻尼比响应面模型,实现模型参数化;基于可靠性分析原理,建立制动器稳定可靠性的功能函数,通过混合参数可靠度计算方法对制动器进行稳定可靠性分析,并用Morris方法对参数化模型的不确定参数进行全局灵敏度分析。用该方法对某型轿车的盘式制动器进行研究,分析得到该制动器系统的稳定可靠度与不确定参数的灵敏度;在稳定可靠度不理想的情况下,根据灵敏度分析结果,通过降低支撑背板密度和增加支撑背板厚度提高盘式制动器系统的稳定性。

To suppress the brake noise of automotive disc brake systems,a stability analysis method of disc brake systems with random and fuzzy parameters was proposed. The proposed method was mainly based on the techniques of response surface methodology（ RSM）,complex eigenvalue analysis and reliability analysis. In the proposed method,the hybrid uncertainties existing in a disc brake system were described by random and fuzzy parameters,and the parameterized model of the damping ratio of unstable mode was established by RSM. The limit state function used to value system stable reliability was built up,and the reliability analysis was carried out for the uncertain brake system with random and fuzzy parameters. In order to explore the influence of system parameters on system stability,the parameter sensitivities were carried out by the global sensitivity analysis of Morris method. By introducing the proposed method for the stability analysis of a disc brake system with random and fuzzy parameters,the reliability and the parameter sensitivities were calculated. The numerical results show that the stability of this brake system can be improved by reducing the densities of back plates or by increasing the thicknesses of back plates.