Nonlinear dynamics of railway wheelsets incorporating randomness

Abstract

The thesis is to investigate the dynamic behavior of a single-axle railway wheelset and identify its chaotic behavior by means of time history, phase portrait, Lyapunov exponents, information dimension, bifurcation diagram and control strategy. The thesis has its analytical and computational components. For the analytical component, several mathematical models of a single-axle rail vehicle wheelset are presented in order to compare their features for similarities and differences. These models present different contact theories of creep force, and have different parametric values. In addition, Model III does not consider gravitational stiffnesses and gyroscopic couple. As a result, directly comparing simulation results of these models makes it difficult to interpret results and to draw conclusions. Therefore, these models need to be expanded so that issues can be isolated and investigated accordingly.