Brake squeal performance comparison between solid and ventilated railway brake disc using the complex eigenvalue method

Abstract Rail transport is one of the two primary means of land transport, next to road transport. One of the issues associated with trains is noise pollution, mainly resulting from the vibrations and high-pitched noise generated by the friction in the railway braking system. This frictional nature induces vibrations that are a significant source of discomfort during train operation. Brake noise has been classified into several categories by engineers and researchers, with squeal being the most significant because it is induced by friction. Despite the growing research on predicting and suppressing squeal noise, most efforts have been concentrated on the automobile industry. Brake noise in the railway sector has been rarely addressed in the available literature. In recent years, significant advances in computing have led researchers to utilize the Finite Element Method to address the phenomenon of vibration generation. This work proposes an iterative method that uses complex eigenvalue analysis, which correlates brake component material characteristics, coefficient of friction, and geometric parameters to instability parameters such as frequency, number of instability modes, and their intensity. To evaluate solid and ventilated railway brake discs performance, three objectives are established: Maximize first unstable frequency FUF, minimize TUF, the total number of unstable frequency and Minimize NI, noise index. Our study yielded intriguing results, including the observation that reducing brake pad thickness, whether through design choices or natural wear, increases total unstable points and shifts instabilities to lower frequencies.Ultimately, our research highlights the importance of various parameters in solid and ventilated railway brake disc system instability.