The Study Of Crash-Resistant Structure For Straddle-Type Monorail Vehicle

With the development of track train technology, active protection technology has become an essential technology of safe operation of trains, but its complexity and random factors still result in occasional train collisions. Therefore, passive safety protection technology is increasingly being taken seriously and used on the train body structure. This paper used the passive safety technology for the straddle-type monorail vehicles as study case, using numerical simulation method to analyze its impact-resistant properties.Firstly, a summary of the nationwide and worldwide research status of the passive safety technology on straddle-type monorail vehicles trains and their classification and characteristics of collisions is presented. The related theories about vehicle collision simulation are introduced, including train collision nonlinear finite element analysis equations, nonlinear characteristics, contact problems and hourglass control arising during collisions.Secondly, detailed analysis of the actual structure of the straddle-type monorail vehicle head, middle of the body, coupler and draft gear and track beam is carried out and the detailed finite element model is developed. In particular, for the characteristics of rubber tires of the straddle-type monorail vehicle, finite element simulation is performed on the choice of the air balloon and elastomeric material on walking wheel, guide wheel, stabilizing wheel. Also, the collision simulation in a straight line and a radius of 100m curvature is studied respectively, and it is compared with the traditional rigid wheel scenario. By analyzing the train collision computation time, collision response, energy distribution and bogies displacement in vertical (radial) direction, we conclude that using air bag and elastic material for tire simulation is more accurate in terms of the actual condition.Finally, for the operating conditions of six train straddle-type monorail vehicle set at a certain speed on a straight track hitting the same train in a stationary or non-braking state, according to the requirements of the standard, combined with the structural characteristics of the straddle-type monorail vehicles, the evaluation criteria and the method for solving the maximum security collision speed are proposed. The simulation result shows that the maximum security collision speed is 20km/h. Therefore, for the problem that the maximum safety collision speed limit is too small, the cause is due to its large interface force and the poor effect of the dissipated energy of the energy-absorbing structure, which results in a too large deceleration.