Influence of Draft Gear Modeling on Dynamics Simulation for Heavy-Haul Train

Abstract

In order to study the impedance characteristics of the frictional draft gear, MT-2 draft gear is studied, and its mechanical properties are analyzed firstly. Then, the mathematical models of two common draft gears are established based on the data collected from the vehicle impact test, and the effects of the two modeling methods on the simulation results are compared through the shunting impact test and the bench test simulation. Researches show that, under various experimental conditions, the simulated draft gear characteristic curve of the lookup table model moves along a fixed trajectory regardless of the change rate of the draft gear stroke, while simulation results of the wedge-spring model depend on the change rate of the draft gear stroke and are more consistent with the experimental results, reflecting the dynamic characteristics of the draft gear and suggesting better adaptability and wider application. Finally, the “1 + 1” grouped 20,000-ton heavy-haul combined train model is established, with its draft gear characteristics under the full-braking condition on flat straight track analyzed. Calculation results and test results of the lookup table model and the wedge-spring model are compared, indicating that using the wedge-spring model to calculate the longitudinal dynamics performance is more accurate. The influence of the modeling on the longitudinal impulse simulation of the train after air braking is also studied, revealing that the variation trends of the coupler force curves of two models are basically the same, but the amplitude and frequency of the longitudinal impulse are different.

A Modeling Method for the Driving Process of Heavy-Haul Train Based on Multi-Mass Model

“…Due to the complex and changeable line condition of freight train and large hysteresis characteristics of air braking of heavy-haul train, the changes in operating conditions of heavy-haul train are complicated, and the control accuracy and response efficiency of the speed following control algorithm have high requirements [41][42]. The fuzzy PID control algorithm has the high precision of the PID control method and the high robustness and fast response characteristics of the fuzzy control algorithm.…”

Dynamic Characteristics of Metro Trains under Rescue Conditions

“…In general, the main course of the longitudinal impulse of a heavy-haul train is the unsynchronized behavior of the rolling stock due to signal transmission. In order to alleviate the longitudinal impulse of heavy-haul trains, the main measures studied at present include ① new technology development, for example, the development and application of ECP technology [7,8], and ② optimization of existing equipment, such as the modeling and optimization of the draft gear system [9,10], as well as the air brake systems [11]. On the other side, lots of longitudinal train dynamics simulators are developed [12,13].…”