Study On Longitudinal Impulse And Wheel-rail Adhesion State For Heavy Haul Train

In this thesis,a multi-body dynamics software UM is used to establish a heavy haul train model;through comparison and analysis of several wheel-rail contact algorithms,an algorithm suitable for this model is selected;the longitudinal impulse characteristics of heavy-duty train under different working conditions and corresponding line conditions,and the influence of longitudinal impulse on the wheel-rail adhesion state of the vehicles under traction driving conditions were studied,and corresponding conclusions were obtained.The research work of this paper has the following aspects:(1)The heavy haul train model is established and the wheel rail contact algorithm is selected.The multi-body dynamics software UM is used to build a heavy-duty train model.The combined train model mainly includes four parts: three-dimensional heavy haul locomotives,three-dimensional trucks,one-dimensional trucks and hook-relaxing devices.Dynamic simulation analysis of train longitudinal impulse and wheel rail adhesion of locomotives is realized.The three kinds of creep force algorithm Mueller algorithm,FASTSIM algorithm and Minov algorithm are analyzed and compared respectively.Finally,the FASTSIM creep force algorithm was finally used to analyze the adhesion of the model in this paper.The train longitudinal impulse and its distribution law along the coupler under different working conditions,different speeds and corresponding routes is analyzed.(2)Heavy haul trains travel on straight and curved tracks respectively.It is found that when the heavy haul train travels on a curved track,its longitudinal coupler force increases sharply compared with the straight-line track;when the train runs at different track radii,the longitudinal impulse size decreases with the increase of the orbit radius,and the maximum impulse is located at the rear of the train.Changing the speed of the train,it is found that when the train speed increases gradually,the longitudinal impulse appears to gradually decrease;When a brake is applied to a heavy haul train,the magnitude of its longitudinal impulse is multiplied,and it tends to stabilize in a very short time.(3)The influence of the longitudinal vibration of the wheel caused by the longitudinal impulse of the train on the adhesion state of the locomotive is studied when the heavy train is in the traction condition and different line conditions.When the heavy haul train is in the traction mode and runs on the straight track,the wheel-rail adhesion vibration of thelocomotive will change from a large amplitude to a steady state when the longitudinal vibration is greatly changed;when a heavy haul train is in a traction mode and is operating on a curved track,the inner wheel of the locomotive has less shorter vibration cycle than the outer wheel.