A. Bhaskar et al., WHEEL-RAIL DYNAMICS WITH CLOSELY CONFORMAL CONTACT .1. DYNAMIC MODELING AND STABILITY ANALYSIS, Proceedings of the Institution of Mechanical Engineers. Part F, Journal of rail and rapid transit, 211(1), 1997, pp. 11-26
Observations on the Vancouver mass transit system suggest that noise,
Vibration and corrugation of the rail appear to be associated with clo
se conformity between the transverse profiles of the wheel and mil. To
investigate this, a dynamic model of the wheel and rail under conditi
ons of close conformity has been developed. Previous work has suggeste
d that motion of the wheel could be neglected, so the model comprises
two subsystems: (a) the rail and its supports, and (b) the contact bet
ween wheel and rail. A dynamic model of a continuously supported rail
is presented which is consistent with similar models in the literature
. Conformal contact has been represented in two ways: (a) as a single
highly eccentric elliptical contact, and (b) as a two-point contact. N
ovel 'rolling contact mechanics' have been incorporated in both these
models. The complete system is closed: oscillations of the rail give r
ise to fluctuating contact forces, which in turn excite the rail. A li
near stability analysis of the system shows it to be stable under all
conditions examined? thus precluding the possibility of self-excited o
scillations occurring on a perfectly smooth rail. The model can then b
e used to investigate the forced response to existing roughness on the
railhead, which is the subject of a companion paper (1).