Thesis-1996-Li.pdf (5.84 MB)
The dynamics of perfect steering bogie vehicles and its improvement with a reconfigurable mechanism
thesis
posted on 2017-06-21, 10:43 authored by Wei [Mech Eng] LiEven since railway vehicles were invented, railway scientists and engineers have
been putting a lot of effort in finding the solution to the fundamental conflict
between vehicle stability in the lateral plane and vehicle's capability of negotiating
curves. Many configurations of railway bogie vehicles have been proposed and
applied to minimise the conflict. The purpose of the research project is i) to create
new configurations that can decouple the basic conflict, ii) to investigate dynamic
behaviour of the new configurations and iii) to conceive a new mechanism that can
improve the dynamics of the new configurations.
Three configurations of body-steered bogie vehicles have been set up in the
research. The sufficient conditions for them to be capable of perfect steering have
been derived. They are called perfect steering vehicles when they satisfy these
sufficient conditions. Their curving ability, stability and ride performance have been
investigated. To overcome the disadvantages of the perfect steering vehicles, the
reconfigurable mechanism has been conceived. The improvement in the dynamic
behaviour of the perfect steering vehicles with the reconfigurable mechanism has
been demonstrated. A computer program has been developed to undertake the
simulation.
The steering capability of the perfect steering vehicles is much better than that of
conventional bogie vehicles. There are two modes of instability in the perfect
steering vehicles: low conicity instability and conventional instability in the perfect
steering vehicle. The perfect steering vehicles can decouple the conflict between
their conventional stability and curving. The improvement of stability and ride
performance of the perfect steering vehicles is, however, limited by the low conicity
instability.
When the reconfigurable mechanism is applied, a body-steered bogie vehicle can
become a perfect steering vehicle when on curves and can become a conventional
bogie vehicle when in other circumstances. Low conicity instability can be
eliminated when the reconfigurable mechanism is used. This class of vehicles
possess the advantages of both conventional bogie vehicles and perfect steering
vehicles, and thus, provide a very valuable solution for the fundamental conflicts
between the stability and steering ability and between ride performance and stability
of railway vehicles. The findings in this thesis have great significance in developing
perfect steering vehicles.
History
School
- Mechanical, Electrical and Manufacturing Engineering
Publisher
© Wei LiPublisher statement
This work is made available according to the conditions of the Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International (CC BY-NC-ND 4.0) licence. Full details of this licence are available at: https://creativecommons.org/licenses/by-nc-nd/4.0/Publication date
1995Notes
A Doctoral Thesis. Submitted in partial fulfilment of the requirements for the award of Doctor of Philosophy of Loughborough University.Language
- en