Research On Track Structure Dynamic Properties For Small Radius Curve Heavy Haul Railway

Due to the increase of heavy haul freight train’s running speed and axle load, the wheel-rail force on the curve has increased, and the wear between wheel and rail become serious, which causes rail wear problems, the deterioration of operating conditions increase maintenance costs and time, all of above have restricted the development of heavy haul railway transportation. Therefore, this paper carries out in-depth research on track structure dynamic properties for small radius curve heavy haul railway, as follows in detail:(1) First, from the current development of heavy haul railway transportation, the significance and urgency of the research on track structure dynamic properties for small radius curve heavy haul railway and action mechanism of wheel-rail wear are expounded.(2) Establishing a detailed dynamic vehiele model, and using the results of field experiments validate the reasonableness of the dynamic simulation model results.(3) The dynamic characteristics for an actual small radius curve and different radius curves were studied. The conclusions show that:when the heavy haul trains run through small radius curves, higher response is caused by the one and three guide wheels, guide wheels are more likely to cause abrasion on the outside of the rail. The wear caused by one wheel on the outside rail is higher than on the inside rail.With the decrease of the radius of the curve, the wheel hedge angle increases, wheel lateral displacement increases, the wheel posts on the outside rail, wheel and rail wear gradually increase, the outside rail is worn more seriously than inside rail, the wheel-rail wear problem are seriously affected by the curve radius. From the reducing wheel and rail wear point of view, the small radius curves should be minimized.(4) Based on the measured rail profile, the dynamic characteristics under different degrees of rail wear are analyzed. The conclusions show that:with the increasing in the degree of rail wear, the maximum wear index of the outside rail and the inside rail are gradually increased and undulate upward trend. Overall, with the wear of rail adding, contact relationship between the geometric changes. Wheel lateral displacement, angle of attack, the wheel-rail lateral force radiate an increasing trend, and thus exacerbated the wheel and rail wear. Therefore, to reduce wheel and rail wear point of view, the rail should be regularly polished, thereby improving the match relationship between the wheel-rail contact.(5) Analyze the influence of the changes to the ultra, rail cant on the dynamic characteristics. The conclusions show that:with the ultra decreasing, the inside rail vertical force reduces, and the outside rail vertical force increases, the rail wheel-rail vertical and lateral distribute more reasonably. At the same time, each wheel angle also showed a decreasing trend hedge, both inside and outside rail wheel-rail wear situation is to slow down, effectively raising the train curves through capability. When using the inside rail cant1:20and the outside rail cant1:40asymmetric setting, it could increas the rolling radius of the circle. Under the same rolling radius difference, a smaller wheel lateral displacement is needed. It’s effective to improve the wheel-rail contact point position, reducing wear on the outerside rail.