Complex eigenvalue analysis of railway wheel/rail squeal

Abstract

Wheel/rail squeal noise of trains is one of the challenging problems of trains, but a successful model for the squeal problem has not been presented until now. In this study, a new approach was presented to investigate the basic mechanism of the wheel/rail squeal noise, using complex eigenvalue analysis by the finite element method. The positive real parts of the eigenvalues reflect self-exciting instable vibration, which is closely related to the occurrence of squeal noise. The effect of parameters such as friction coefficient, wheel/rail contact position, axle load, etc. on the instable vibration was examined. The instability of the vibration system was sensitive to the stiffness of rail support. In lateral creepage when the adhesion coefficient was less than 0.1, instable vibration modes did not occur. In longitudinal creepage, when the friction coefficient was high enough, instable vibration modes were generated. Numerical predictions could explain many of the field test results.

Keywords: Wheel, Rail, Squeal, Finite element, Complex eigenvalue, Contact