Hopf bifurcation and nonlinear oscillations in railway vehicle systems

Hopf bifurcations and nonlinear oscillations for a railway passenger car ar e studied in this article. The vehicle is considered as a multi-rigid-body system with 17 degrees of freedom. During the wheel/rail impact when the wh eelset lateral displacement is greater than the wheel flange clearance, the vehicle/track coupling model is considered. The rail is modelled as an Eul er-Bernoulli beam extended to infinity and discretely supported by sleepers . The lateral and torsional vibration of the rail is taken into account. Tw o propositions for searching the Hopf bifurcation point of the system are g iven. Then linear and nonlinear critical speeds of the vehicle system with different primary suspension stiffness, periodic solutions and chaos in the system are investigated.