Bifurcation analysis of a railway wheelset with nonlinear wheel–rail contact

Stability is a key factor for the operation safety of railway vehicles, while current work employs linearized and simplified wheel/rail contact to study bifurcation mechanism assess stability. To stability characters under real nonlinear contact, fully parameterized vehicle wheelset model built. In modeling, geometry nonlinearities wheel rail profiles come from field measurements, including rolling radius, angle, curvatures, etc. Firstly, four flange force models their effects on bifurcations are compared. It shows that an exponent fitting more proper than quintic polynomial one simulate works well without changing Hopf type. Then each term limit circle discussed. Both linear radius have significant influence point (LPC) bifurcation. The critical speed (Hopf point) (LPC changes times within calculated range radius. Its type almost by half. angle curvature should be taken into consideration since they can change both type, cubic ignored. Furtherly, measured several running mileages employed examine corresponding behavior. result larger suspension stiffness would increase wear.