Investigations on the vertical buckling of railway vehicle’s anti-climber

Abstract

From accident investigations it is found that under some unknown conditions the energy absorbing capacity and anti-overriding function of anti-climber are greatly reduced due to the serious vertical buckling. In order to analyse the vertical buckling mechanism of collided anti-climber, a simulation strategy based on the coupling finite element method and multi-body dynamics is proposed in this paper. A numerical model of anti-climber is established and validated with the quasi-static crush test. The simulation results indicate that in some train collisions the maximal overriding speed can increase as large as 1.5 m/s. Under this condition, large constraint force and bending moment are induced and applied on the collided anti-climber, resulting in a serious vertical buckling. Besides that, the initial vertical offset is identified as another important factor. Generally speaking, the buckling degree as well as the deterioration of energy absorption capacity of collided anti-climber becomes more severe with the increase of initial offset. Moreover, when the two factors (initial vertical offset and overriding speed) are coupled together, the crush behaviour of anti-climber is more complex. If the bending moments, which are induced by the initial vertical offset and overriding speed respectively, are in the same direction, the collided anti-climber is buckled seriously. On the other hand, if these bending moments are in the opposite directions, they are counteracted. As a result, the collided anti-climber is buckled less seriously and has more capacity to absorb the collision energy.