Overriding Behavior in Train Collisions Based on Moving Vehicle-Track Coupled Model

In order to reveal how vehicle parameters affect the overriding behavior in train collisions, the vehicle model and the moving track model were developed in view of the basic ideas of vehicle-track interaction. The nonlinear wheel-rail contact model was applied in coupling both models. A nonlinear coupler model was used to connect two adjacent vehicle models. Then the head-on collision of two identical trains was simulated at low speeds. The dynamic responses of vehicles and tracks were obtained with different parameters. Finally, the wheel lift was taken as the vehicle-collision overriding index. The sensitivity and the relative sensitivity were analyzed in terms of wheel lift to impact speed, to height of car body mass center and to vertical stiffness of secondary suspensions. The results indicate that when other conditions remain unchanged, the wheel lift rapidly increases to 36.5 mm if the impact speed increases to 27 km/h. The wheel lift increases by 41% when the height of mass center increases by 20%. However, it decreases by 16.6% if the vertical stiffness of secondary suspension increases by 20%. In other words, the wheel lift increases with the impact speed and height of mass center, and decreases with the vertical stiffness. The sensitivity of wheel lift to impact speed is nonlinear. The relative sensitivities of wheel lift to height of mass center and vertical stiffness are 205% and −83%, respectively.