Development of a vehicle–track model assembly and numerical method for simulation of wheel–rail dynamic interaction due to unsupported sleepers

Abstract

2010)Development of a vehicle-track model assembly and numerical method for simulation of wheel-rail dynamic interaction due to unsupported sleepers, Vehicle System Dynamics: International Journal of Vehicle Mechanics and Mobility, 48:12, 1535-1552 To link to this article: http://dx.In practice, it is not very uncommon to find railway track systems with unsupported sleepers due to the uneven settlement of a ballasted track system. These unsupported sleepers are among the major vibration excitations for a train and track system when a train moves forwards on a track. The vibration induced by unsupported sleepers can cause a large dynamic contact force between wheels and rails. For heavily loaded high-speed trains, the deteriorated sleeper support may lead to accelerated degradation of the railway track and vehicle components, and may thus impose safety risk to the operation. This paper presents analyses of a coupled vehicle-track assembly consisting of a roll plane vehicle model, a continuous track system model and an adaptive wheel-rail contact model. In order to improve the simulation efficiency, a numerical approach based on the central finite difference method is proposed in this investigation. The developed model assembly and proposed simulation method are utilised to simulate the vehicle-track dynamic interaction in the presence of unsupported sleepers. The dynamic response in terms of the dynamic wheel-rail interaction force due to one or multiple unsupported sleepers is studied. Important factors influencing the dynamic wheel-rail interaction force in the presence of sleeper voids are also investigated. The results show that the vehicle speed, the gap size and the number of unsupported sleepers primarily dictate the magnitude of impact load which can be significant.

The Effect of Unsupported Sleepers/Bearers on Dynamic Phenomena of a Railway Turnout System under Impact Loads

“…By contrast, their study also shows that local maxima could be observed in different configurations considering the number of hanging sleepers, vehicle speed and the height of gap configurations. In another study [7], by means of configuration, several scenarios for a one-sided partially unsupported sleepers was simulated and resulted in similar conclusions such that higher speed increase the contact force variations. They also show that the effect of triangular configuration, where three assumed voids are sequentially placed under left, right and then left rails, have no significant effect on the contact forces.…”

Influence of Rail Pad Stiffness and Axle Loads on Dynamic Responses of Train-track Interaction with Unsupported Sleepers

“…Kaewunruen and Remennikov [8] conducted several laboratory studies on the effect of unsupported sleepers on modal analysis and consequences of vibration modes on the track. Zhu et al [9] investigated the effect of vehicle speed, gap size and the number of unsupported sleepers by assuming a continuous track system model and an adaptive wheel-rail contact model. Rezaei and Dahlberg [10] by presenting their cross-section model of track, showed that the effect of pad stiffness is negligible on sleeper dominant frequency and the effective parameters are sleepers flexural stiffness, mass, and its distribution .…”

“…(21). Considering the last wheel crossing the track, the calculating time can (9) be computed through Eq. (22), where l0 is the rigid wheelbase of the wagon and l is the length of the selected track.…”

Effects of Rail Cant on Wheel-Rail Contact Forces in Slab Tracks

“…6-The fundamentals of derailment are based on the Nadal formula which is an international formula. The equation of this theory is (Iwnicki, 1998 andZhu et al, 2010):…”