汽车盘制动器优化设计热和机械特性的研究(一)

A Study of Thermal And Mechanical Behaviour For the Design of Automotive Disc Brakes

由于热量集中于制动盘的表面造成热弹不稳定性(TEI)而引起热变形。这样可能发生大家知道的低频强烈振动。因为在盘和衬块的接触面间的摩擦系数变化,在摩擦衬块发生尖叫声。通过对热聚集和尖叫现象的联合分析,对高热和机械特性可设计一最佳的盘和摩擦衬块。本文同时考虑了热和机械不稳定性按照盘的厚度,卡钳的加压方式,衬片弧长进行了数值和实验分析。采用有限元分析法(FEA)计算了热变形和压力分布。采用汽车底盘测功器和高速红外摄像仪进行实验评估TEI性能,结果用FEA修正。采用FEA估计机械不稳定性进行复杂固有值分析,按照转子和摩擦衬盘的形状对于一固有值问题应用修正仿真结果分析接合形式。在热聚集和尖叫问题期间,讨论因考虑盘制动器性能盘和摩擦衬块的设计。

The thermal distortion induced by thermoelastic instability（TEI） results in hot spots on the surface of the brake disc. This can incur low-frequency vibration known as judder. In pad-induced squeal noise, mode coupling occurs owing to the variation in the friction coefficient between the disc and pad, inducing high-frequency noise. Through a coupled analysis of hot spots and squeal phenomena, an optimum disc and pad design can be designed for higher thermal and mechanical performance. In this study, numerical and experimental analyses are performed in accordance with disc thickness, pressurization type of caliper, and lining arc length, considering thermal and mechanical instability simultaneously. Thermal deformation and pressure distribution are calculated using a finite element analysis（FEA）. For evaluating TEI performance, experiments are performed using a chassis dynamometer and a high-speed infrared camera, and the results are correlated with FEA results. A complex eigenvalue analysis is conducted to evaluate mechanical instability using an FEA. Modal testing and simulations are conducted to correlated a real model and an FE model, and the corrected simulation results are applied for a complex eigenvalue problem to analyse coupled modes according to rotor and pad shapes. The results on disc brake performances considering the disc and pad design are discussed in terms of hot spots and squeal problems.