Study on the collision characteristics of a subway coupler

Abstract

Derailment accidents caused by coupler buffer devices should not be underestimated. In this study, a particular type of subway was considered the research object, and a nonlinear finite element model of train collisions with a detailed coupler was established to study the collision characteristics of the coupler under different working conditions. First, the nonlinear mechanical characteristics of the coupler were analyzed. Then, a finite element model, including the energy absorption characteristics of the buffer and the collapse tube, the failure characteristics of the overload protection device, and the motion characteristics of the nodding and shaking head, was established and its reliability was verified. On this basis, a collision finite element model of a subway with four sections was developed. The attitude motion of the couplers and its influence on the derailment behavior of the vehicle was studied under the condition of initial vertical deviation or lateral deviation of the active and passive head couplers during their operation period. The results show that when the collision velocities are equal, the initial state of the head coupler barely affects the axial action characteristics and the pitching deflection angle attitude of the middle couplers; however, it has a certain effect on the yaw deflection angle. Furthermore, the initial state of the head coupler has a significant influence on its motion. The initial vertical deviation of the head coupler increases the derailment risk of the second section of the active subway. Moreover, the initial lateral deviation of the head coupler increases the derailment risk of the active subway and the first section of the passive subway. When the utilization rate of the head coupler is approximately 69%, the derailment risk of the vehicle is reduced.