Research On Longitudinal And Lateral Load Of Heavy Haul Train

Heavy freight transportation is the major development orientation of railway freightage techniques in the world. Since the60’s, the countries, which have wide territory associated with large quantity of shipments, have made use of heavy haul trains. In recent years, the requirement of railway transportation capicaty is continuely increasing due to our rapid development of national economic and shipments sharply increasing.It is the main method of developing high-speed heavy freight to improve our country’s railway transportation efficiency and reduce operation costs. Along with the development of heavy freight transportation, there is a highly possibility for our country to develop20,000ton or even more traction tonnage freight transportation. However, because of the increasing traction tonnage and the length of train of locomotive, the longitudinal and lateral dynamic loads which loaded on body between coupler and draft gear will sharply increase. The longitudinal and lateral loads which sharply increase could not only make worse of the coup injury of body and draft gea. as well as fatigue break-down due to dynamic loads, but also could even cause off hook and unhook in serious condition which could affect the safty performance when train’s running. So. it is necessary to analyze the longitudinal and lateral loads to guarantee the safety of heavy fright train.Based on the causes discussed above, this paper make studies on heavy freight train’s longitudinal and lateral loads, which including the major tasks as follow in details:1. Building the longitudinal dynamic simulation model according to the theory of longitudinal dynamics fully considering the forces which effect on trains in the procedure of modeling, listing the kinetic equations of the train, using4order Runge-Kutta method to solve equation.2. Calculating the coupler force of train at different traction weight conditions. The result shows that the biggest coupler force is the pull of coups that appears in the front of train in the ingle encoding condition of train traction and appears in the2/3of train in braking condition; the smaller coupler force is conductive to reduce the maximum coupler force; the combine of "1＋2＋1" heavy freight train synchronous breaking has better dynamic performance than2s delaying braking, and a great coupler force will appear when the brake is applied on the train running in a low speed.3. According to the train position on the curve, calculating transverse component of longitudinal coupler force, then transform the transverse component to the centre plate; according to the structural features of three parts freight bogie, simplify the degrees of freedom advisably, established lateral dynamics model; according to Hertz contact theory and Kalker linear creep theory, gain the creep force between the wheel and track; use Newmark-β modus solving dynamic model.4. Dynamic curve negotiating is simulated, in order to ensure the effect of length of transition curve line and radius of curve to the vehicle dynamics curve performance. The results show that a shorter radius of curve and a longer transition curve line is more benefit to the vehicle dynamics curve performance. It is indicated that The lateral force between wheel and rail in heavy vehicle operating conditions is bigger than it in empty condition, but the derailment coefficient and the rate of wheel load reduction rail in heavy vehicle operating conditions are smaller than it in empty condition. The vehicle dynamics curve performance of empty vehicle is worse than heavy vehicle.