Simulation Study On Longitudinal Dynamics Of Heavy Haul Train

Heavy haul railway transportation is widely valued by railways all around the world due to its large transport capacity, high efficiency and low transport cost. Since the 1980 s when the first electrified heavy haul railway--daqin line was built in our country, heavy haul transportation has been developing rapidly in our country. But, with the increase of transport capacity, train loading and formation length, the longitudinal load born by car-body and the coupler buffer device is increased rapidly. The sharply increased vehicle longitudinal load doesn't not only exacerbate the direct damage of car-body&the coupler buffer system's components and the fatigue failure under dynamic loading, it will also result in coupling break or decoupling when it's serious.In light of the above problems, this paper established the multi-particle longitudinal dynamic model and the coupler buffer model of heavy haul trains, it mainly includes the longitudinal dynamic model of trains, the resistance calculation model of trains, the locomotive traction and brake model, the truck brake model and the coupler buffer model; And analyzes the causes of longitudinal impulse and the important factors that affect the longitudinal impulse.Second, Based on the Simpack simulation software, the simulation of long trains formation's longitudinal dynamic model was performed and the articulated and force element model of rail vehicles was established. The emergency braking condition of the train longitudinal dynamics model is simulated and the results are basically consistent with the experimental results.Third, real-time calculation research of long trains' longitudinal dynamics was performed. Based on the dynamic calculation methods of Runge-Kutta method and Newmark-?, the comparison of the advantages&disadvantages of these tow methods and error analysis were conducted. Based on the optimized fourth-order Runge-Kutta method, the coupler force of heavy haul trains was worked out through programming iteration. And, the simulation result, the Simpack simulation data and the test data were analyzed and compared.At last, simulation research of vehicles' coupler buffer model was performed with VC software and the optimized Newmark-? method. A set of simulation software of heavy haul trains--the longitudinal dynamics calculation system of trains was developed. By different marshalling situations, real-time calculation of the coupler force and visual display of trains under the two conditions of traction and emergency braking were realized. In addition, according to calculation cases simulation, the changes and distribution condition of coupler buffer devices' maximum coupler force along the total length of trains were obtained and the results were analyzed and summarized.