Constraint equations between the wheelset and rails on straight railway track

Abstract

The rolling angle and the vertical displacement of the centre of gravity of the wheelset are not independent degrees of freedom while the wheelset runs on railway track. On straight track, the effects of the lateral displacement of the wheelset, of the lateral and vertical displacements of the neutral axis of the left and right rails, of roll around the centre roll of the left and right rails, of the longitudinal profile and lateral alignment irregularities of the left and right rails, and of the conicity of the left and right wheel treads on the rolling angle and the vertical displacement of the centre of gravity of the wheelset are considered in this paper. A generalized spatial rail beam element is presented. The finite element forms of the constraint equations for rolling angle, rolling angular velocity, rolling angular acceleration, vertical displacement, vertical velocity and vertical acceleration of the centre of gravity of the wheelset are expressed by the dependent factors mentioned above. These equations can be useful in three-dimensional vehicle/track interaction modelling.