The Exploration Of The Evaluation Methods For Small Radius Curving Performance

With low speed of the train negotiating the small radius curve and hard to be developed, and poor operational safety and stability, frequent derailment accident,which has seriously affected the development of the national economy and transportation needs. Therefore, on the basis of ensuring security, it should try to improve the speed of the train through the curve, but too high speed will increase the wheel-rail force, and while the speed is too low, it could easily lead to wheel load reduction and increased the likelihood of derailment, and there exist irregularity in the actural line and the down slope on the transition curves, it is necessary to analyze the security of the vehicle negotiating the small radius curve, and find out the influence of track irregularity on the performance of the vehicle through the small radius curve and also the limited speed.According to the certain A1A (power with four driving equipments mounted in the frame of six axles) DMUs and the HXD1B high-power AC drive electric locomotive, using multi-rigid-body dynamics software SIMPACK establish the dynamic model of the motor car and the locomotive, simulation analysis of the power car and the locomotive negotiating the small radius curve is done under different conditions, and compared with the test, the results showed that, the effect of the Local Irregularity on the dynamic performance of the power car was not more than5%of the mearued maximum, while the Random Irregularity accounted for60%. There exist difference of track irregularity at different locations and also at different directions in the actual line, the overall, the track irregularity used in the simulation for the evaluated value in the test of each dynamic index is larger than that for the average value. The actural running transverse irregularity of the locomotive remained the same with the power car, while the vertical irregularity is one level larger, and for different lines, the difference of each direction is not the same. Therefore, the irregulatiry difference of different line should be considered in future simulation analysis.By comparing the simulation result of the HXD1B high-power AC drive electric locomotive negotiating the small radius curve with the test, it showed that, the data processing method has a great influence on the small radius curving performance of the locomotive, the wheel-set lateral force and wheel load rate reduced on the sliding means over2m compared with that over a quarter circumference, so as the waveform amplitude, while curve smoothness improved. The statistics of derailment coefficient reduced after sliding mean and the high frequency interference signal has been eliminated, and the larger the wavelength and the track irregularity, the greater the influence of data processing method on the dynamic performance of the locomotive.By analyzing the speed limit of the A1A power car negotiating the small radius curve, indicating that the highest limited speed of the passing car on the small radius curve was mainly influenced by various factors, such as the susperelevation of outer rail curve radius, track irregularity and limit value of the wheel-rail lateral force, etc.The wheel-rail lateral force exceeded the limit first, as long as the wheel-rail lateral force did not exceed the safety limit value, other dynamic indexes should also meet the requirement, and account for the test, the worst dynamic performance of the power car appeared at the transition point, and the transverse irregularity of the actural line at the transition point was close to that of the poor line, Thus, the limited negotiation speed of the power car on small radius curve should be evaluated by the maximum wheel-rail lateral force limit value of the poor condition.