Study on Numerical Auclysis of Longitudinal Forces of the T20,000 Heavy Haul

The longitudinal dynamics model of heavy haul trains is presented.The dry friction damping hysteretic characteristic of steel friction draft gears is simulated by the equation which describes the suspension forces in the suspension system.The dynamic characteristic curve of the draft gears is buiet up by the curve-fitted method,which is based on results of a large number of impact tests.Consequently,the numerical model of the draft gears is brought forware.The equation of train longitudinal dynamics is strongly nonlinear.In order to solve the response of the strongly nonlinear system,the high precision and equilibrium iteration method based on the Newmark-β method is presented and numerical analysis is made.According to the principle of the Locotrol synchronizing control equipment,the mathematical locotrol synchfonizing control model is established.Longitudinal dynamic forces of the T20,000 heavy haul train are tested and verified;the influence of the synchronizing response time between the master control locomotive and slave control locomotive and their initial braking velocities on the longitudinal forces of the heavy haul trains are analyzed.The research results provide theoretical basis for study of the optimization operation technique for heavy haul trains.