Effects of Non-Linear Suspension on Hunting and Critical Velocity of Railway Wheelset

In this paper, effects of non-linear suspension on dynamic behavior of a railway wheelset have been studied. Nonlinear dynamic model of wheelset motion has been derived. Four coordinates are used and two constrains have been found, therefore, two degrees of freedom are remained. Contact forces between the wheels and rails have been calculated using Vermeulen-Johnson theory. Constant creep coefficients have been taken into consideration. Lateral suspension is dry friction which has been modeled by using Kolesch theory. Runge-kutta method has been used for solving the equations and results are presented to obtain limit cycles due to hunting behavior of the wheelset.