Wheelset lateral force factor and critical offset distance of the centre pivot of articulated train

Abstract

The longitudinal distance between the centre pivot and the centre of end bogie significantly affects the wheelset lateral force of the outer and inner wheelset. Whether the centre pivot of end bogie of articulated train needs to be offset, and how to set the offset distance, research is still lacking. Taking this as a starting point, this study utilised wheelset lateral force factor to discuss the influence of the centre pivot offset distance on the safety of the wheelset lateral force and derived the formula for calculating the critical offset distance of the centre pivot. Taking an articulated tram with three car bodies and four bogies as an example, a force analysis model for steady-state curve negotiation was established, and the relationship between the wheelset lateral force and the offset distance of the centre pivot was derived, which was verified by the dynamic model. When the maximum value of the wheelset lateral force factor of each bogie reached the minimum, the optimal centre pivot offset distance was obtained, which was called the critical offset distance. The influence of the offset states of the centre pivot on the curving performance of the tram was analysed by the dynamic model. The results showed that derailment coefficient, wheelset lateral force factor, and lateral displacement of end car bodies in the critical offset state were smaller than them in other offset states.