Title 
Nonlinear railway vehicle dynamics 
Author

Gilles, Brieuc

Supervisor

True, Hans (Department of Informatics and Mathematical Modeling, Technical University of Denmark, DTU, DK2800 Kgs. Lyngby, Denmark)

Institution 
Technical University of Denmark, DTU, DK2800 Kgs. Lyngby, Denmark 
Thesis level 
Master's thesis 
Year 
2004 
Abstract 
We investigate the motion of a railway vehicle travelling along a straight track, with constant rolling velocity v. The model contains dryfriction dampers which introduce a stick/slip effect. We consider only three degrees of freedom, so that the impact of the stick/slip phenomenon can be more clearly detected. The dynamics are described by a nonlinear system of equations obtained by applying classical mechanics laws.
The behaviour of the solutions turns out to be highly sensitive to the parameter v, as a complex sequence of bifurcations occurs all across the velocity spectrum 5m/s v 40m/s. Several different types of attractors are found  some are periodic, others are chaotic. We discuss two methods to estimate the largest Lyapunov exponent y1. The standard method involving Gram Schmidt orthonormalizations is found to contain large but systematic errors. We therefore present a simple method for estimating these errors, and use the error estimates as correction terms. The resulting estimates of y1 are used to test for chaotic solutions across the velocity spectrum. 
Imprint 
Department of Informatics and Mathematical Modeling, Technical University of Denmark, DTU : DK2800 Kgs. Lyngby, Denmark 
Keywords 
Nonlinear dynamics; chaos; Lyapunov exponents; bifurcations; railway dynamics; dryfriction; stick/slip. 
Admin 
Creation date: 20060622
Update date: 20121221
Source: dtu
ID: 154753
Original MXD
