Nonlinear Stability and Tracking of Rail Passenger Trucks

An analysis of a rail passenger truck which includes nonlinear wheel/rail geometry and creep forces is formulated for determining truck stability and response to rail alignment irregularities. Digital simulation studies using the analysis have illustrated the large amplitude flange to flange response which occurs in operation of a truck below critical speed on a track with significant alignment irregularity, of a truck near critical speed and excited by irregularities and of a truck operated above critical speed. The variations in temporal waveform, probability density, and power spectral density of vehicle motions for these conditions are described. The influence of vehicle suspension parameters and wheel/rail geometry on truck stability and tracking ability is discussed and related to operating conditions.