Stability analysis, time-domain solutions and vertical dynamics in the modelling of curve squeal generated by rail bound vehicles

A new model of curve squeal generation is presented. Both vertical and lateral wheel-rail contact forces and wheel dynamics are taken into account. The model allows predicting the occurrence of the noise through stability analysis of driving-wheel modes for initial conditions close to the quasi-static slip (linear analysis). In instable cases, the properties of the noise can also be determined through spectral and energy analysis of limit cycles in the time-domain (non-linear analysis). Despite an observed coupling of lateral and vertical dynamics, especially for off-center lateral contact position on the wheel, numerical results show that only a velocity-weakening friction coefficient is able to destabilize the slip and induce wheel vibrations at medium and high frequencies.