Research on Stochastic Stability of Wheelsets with Primary Suspension

Abstract

A new model for elastic constraint wheelset system of rail vehicle is proposed. Assuming the stochastic excitation as Gauss white noise, a stochastic model is built for elastic constraint wheelset system. Here two kinds of stochastic excitations are considered: one is the internal multiplicative excitation inherited in the internal system such as the spring and wheelset/rail contact geometric relationship, the other is the external excitation induced by track random irregularities. The model defined here is considered as a weak damping, weak excitation quasi non-integrable Hamiltonian system. The maximal Lyapunov exponent is calculated by quasi non-integrable Hamiltonian theory and oseledec multiplicative ergodic theory, and the stochastic local stability conditions are obtained. Meanwhile, the stochastic global stability conditions are derived by considering the modality of the singular boundary condition.