Forecast And Analysis Of 10000t Train Of Longitudinal Impulse For 30t Axle Load Vehichle

Since the 1980 s, the research of heavy haulage technology on speed and heavy load, make China’s railway transportation volume reach its limitation continuously in the limited line mileage, which greatly easing the contradiction of the transportation capacity shortage. Nowadays China’s heavy-haul transport is developed to the heavy axle load direction, which is recognized as one of the most effective ways to improve the efficiency of heavy-haul transport.The universal axle load of heavy-haul line is 25 t in China, 30 t heavy axle load coal open top wagon C96 has been developed and entered to the test phase recently. The heavy-haul trains are easy to lead larger longitudinal impulse affected by the brake asynchronism and braking force inhomogeneity when used the air brake system to brake. In order to ensure the security of the heavy axle load train running, it’s necessary to conduct longitudinal impulse of the train.So the longitudinal dynamic impulse of a 10000-ton rain consisting of 30-ton axle load C96 cars is analyzed and predicted using a train air brake and longitudinal dynamics integrated simulation system.After calculating the longitudinal impulse of trains under the full service brake and emergency brake, compared to C80(10000-ton train with 25-ton axle load)in initial braking speed 80km/h, the maximum coupler force of C96( 10000-ton train with 30-ton axle load)in full service brake is 434 kN, and 1262 kN in emergency brake.It has a reduction of 14.8% under full service brake, and a 2.9% reduction under emergency brake. Through the analysis of the trains in different axle load cars we found that the differences in brake cylinder pressure rising characteristics make the maximum coupler force increase 27.3% and 11% in full service brake and emergency brake respectively, heavier axle load increase 24.3% and 5.9%, the shorter marshalling decrease 36.5% and 13.1%, the lower braking capacity decrease 25.9% and 10.8%. Four kinds of factors totaled decrease 10.8% and 7% respectively. It showed that the differences in brake cylinder pressure rising characteristics, axle load, vehicle number in a train, and car braking ability are the main reasons that the 10000-ton train with 30-ton axle load longitudinal impulse changed.The longitudinal impulse of a 10000-ton train with C96 cars when braking is forecasted in different line conditions, compared to the 10000-ton train with C80 cars, the longitudinal impulse of trains with 30-ton axle load is slightly better than that of trains with 25-ton axle load under the same line(flat + uphill, flat+downhill).Through calculation of cycle braking of the long heavy down grade, found that a 10000-ton train with C96 cars can pass it successfully; the 10000-ton train with C96 cars longitudinal impulse under other conditions are analyzed the longitudinal impulse compared to the 10000-ton trains with C80 cars, found that the longitudinal impulse of trains with 30-ton axle load is slightly better than that of trains with 25-ton axle load under the same release condition. The train can be started by HXD1 locomotive.The locomotive’s tractive characteristics and coupler slacks of vehicles have a direct effect on the train’s longitudinal impulse while in starting condition.