Brake squeal is an important issue in the automotive and railway industry with high frequencies and acoustic pressure (above 1 kHz and 80 dB). For the comfort of passengers, the generation mechanism of this noise needs to be investigated to propose mitigation solutions. Recent works show that the state of the rubbing surface has a strong influence on the occurrences. In this paper, we propose to consider the effect of contact localization on the occurrence of squeal through experiments on a pin-on-disc system close to the braking application. An in-operando and in-situ monitoring of the contact surface during tests is carried out with thermal tracking of the friction body through thermocouples inserted in the pin near the rubbing surface. Based on the thermal measurements, an inverse method is used to identify the heat dissipation zone. Assuming that this zone is equivalent to the macroscopic load-bearing area, a stability analysis is performed to determine the unstable frequencies from contact area. Correlations between numerical results with experiments show that the change of squeal frequencies agrees with the evolution of the contact localization at a macroscopic scale. This localization can then be considered as one of the key parameters linking the surface state and the occurrence of squeal.

制动尖叫是汽车和铁路行业的一个重要问题，具有高频率和高声压（高于 1 kHz 和 80 dB）。为了乘客的舒适度，需要研究这种噪声的产生机制，以提出缓解方案。最近的工作表明，摩擦表面的状态对发生的影响很大。在本文中，我们建议通过在接近制动应用的销盘式系统上进行实验来考虑接触定位对尖叫声发生的影响。在测试期间对接触表面进行现场操作和原位监测，通过插入摩擦表面附近的销中的热电偶对摩擦体进行热跟踪。基于热测量，逆方法用于识别散热区。假设该区域相当于宏观承载区域，则进行稳定性分析以确定接触区域的不稳定频率。数值结果与实验之间的相关性表明，尖叫频率的变化与宏观尺度上接触定位的演变一致。这种定位可以被认为是连接表面状态和尖叫声发生的关键参数之一。