Study On Curve Collision Response And Crashworthiness Of Subway Trains

Subway is one of the most common forms in urban rail transit,and its curve segment accounts for an increasing proportion of operating mileage.At present,collision research is mainly focused on straight line collisions,and lack of studies on curve collision response and crashworthiness of subway trains.In order to study the collision results of subway trains under different influencing factors,4 typical conditions that subway trains collide on curved tracks are designed.This paper analyzes the parameters of track and the initial contact state between wheel and rail.LS-DYNA is used to calculate and analyze these collision simulation models which including the changes of different parameters respectively.This paper adopts four indicators to judge the derailment behavior of vehicles.According to the analysis,the results are as follows:Firstly,with the reduction of the friction coefficient between wheel and rail,the lateral buckling of trains tend to be strong,D1 car is more prone to derailment,vertical arching and overriding while D2 car is opposite,the longitudinal deformation and the deformation absorption energy by the front structure of car body are smaller,the more ratio of initial kinetic energy is converted to sliding energy.Secondly,with the increase of marshalling vehicles,the lateral buckling of trains and the motion posture of couplers become more intensely,the risk of derailment,overriding and rolling of vehicles is higher,some parameters increase gradually,including the longitudinal deformation of car body,the deformation absorption energy by front structure and the ratio that initial kinetic energy is converted to sliding energy.Thirdly,with the decrease of orbit radius,the lateral buckling of train is more obvious,and it is more likely for vehicles to cause derailment and overriding,in the meantime multiple cars may derail.Fourthly,with the promotion of initial speed,it is more risky for vehicles to cause derailment and overriding,the longitudinal deformation of car body and the deformation absorption energy by front structure are increased,but it does not affect the ratio that initial kinetic energy is converted to sliding energy.This paper combines the simulation results and propose 2 security design schemes to improve the safety of subway trains,the results show that when limiting the vertical rotation angle of the intermediate couplers and redistributing the design stroke of the crushing tube,the trains do not show severe lateral buckling,derailment and overriding,the energy absorption utilization of the middle couplers is improved.When installing the anti-climbing and anti-biasing devices at the car ends,it can limit the relative movement between adjacent car ends,restrain the nodding and yaw motions of intermediate couplers,and inhibit lateral buckling,derailment,overriding and rolling of trains.