Semi-analytical approch for brake squeal of a rail pad

In this study, a semi-analytical pad model was developed to analyze the causes and mechanism of brake squeal of a rail pad in a railway brake system. A complex eigenvalue analysis was performed by developing the equation of motion of the contact area using a semi-analytical model. As a result, dynamic instability was indicated by the mode-merging of the z-translation mode and flexible mode of the rail pad. In addition, the z-translation mode of the rail pad has a large frequency change when increasing the contact stiffness, and mode-veering is generated by the surrounding flexible mode along the frequency loci. Therefore, z-translation mode is predicted to be major mode that generates the mode-coupling instability.