| High-speed railway are the major demands of the national transportation development strategy.They are also the important methods to solve the lack of passengers'transportation in China,but they also put forward higher requirements for the operation performance of high-speed EMUs.With the continuous increase of the mileage of high-speed railway and the increasingly dense operation of high-speed EMUs in China,wheel-rail wear and various dynamic problems have gradually begun to be exposed.Wheel-rail wear not only affects the running quality of the vehicle,but also seriously affects the operational economy of the vehicle due to the gradual improvement of wheel reprofile and rail repair costs.Therefore,in order to get the high-quality and high-economic operation of high-speed EMUs,this dissertation considers wheel wear together with the running performance of the stability,comfort and safety of the high-speed EMUs to evaluate the running performance and wheel wear.Based on the rigid-flexible coupling method,the human-carbody coupled multi-body dynamics model is established.The influence of wheel profiles and suspension parameters on the running performance of EMUs is analyzed.The running performance and wheel wear of the existing two types EMUs is analyzed.The evolution of the rail parameters under the condition of small radius curve is discussed.The outcomes of this dissertation play an important role to develop technologies of structural parameters design and rail parameters setting of high-speed trains in China and it can provide a theoretical basis and possible application prospect.This dissertation based on the rigid-flexible coupling method,the high-speed EMUs are taken as the research objects,and the rigid-flexible coupling dynamics model with the vibration mode of carbody is established.This dissertation summarizes and analyzes the evaluation methods on the operation performance of vehicles proposed by different countries and standards-setting organizations,points out the limitations of existing comfort evaluation methods,and builds a human-carbody coupled multi-body dynamics model.By comparing with the measured data,the model can reflect the passenger's ride quality better.Therefore,it is proposed to use the vibration acceleration and Sperling index of the human head position to evaluate the running comfort of the vehicle.This dissertation summarizes and analyzes the wheel-rail contact theory and wheel-rail wear model.Based on the comperation of different wear theories,combined with the theory of wheel-rail contact and the established vehicle system dynamics model,the wheel-rail wear software which can comply automatic iteration is composed.The prediction results are compared with the measured results based on the heavy-haul trains C80BH-K5and CRH380B EMUs to verify the reliability of the wheel-rail wear software.Based on the established human-carbody coupled multi-body dynamics model and the programmed wheel-rail wear software,combined with the proposed operational performance evaluation criteria,the influence of the running performance and wheel wear by the change of the axlebox stiffness and the yaw damper characteristics of the two types EMUs used in China in different wheel profiles is studied.The selection of the suspension parameters to improve one of the running performance of the vehicle with different profiles is proposed.For the vehicles use LM_A tread wheel,in order to get the better running stability and comfort,the small axlebox stiffness should be used with the yaw damper of small stiffness and large damping;For the best running safety,the small axlebox stiffness should be used with the yaw damper of large stiffness and small damping;In order to obtain the best wheel wear,the large axlebox stiffness should be used with the yaw damper of large stiffness and small damping.For the vehicles use LM_B tread wheel,in order to get the better running stability,the large axlebox stiffness should be used with the yaw damper of large stiffness and damping;In order to get the better running comfort,the small axlebox stiffness should be used with the yaw damper of small stiffness and large damping;For the best running safety,the small axlebox stiffness should be used with the yaw damper of large stiffness and small damping;In order to obtain the best wheel wear,the small axlebox stiffness should be used with the yaw damper of small stiffness and small damping.Based on the existing suspension parameters and wheel profiles of the two types of Type CRH380A and Type CRH380B EMUs,which called Type A EMUs and Type B EMUs below,the evolution process of the running performance and wheel wear of the vehicle with the increase of operating mileage is studied,and the running performance and wheel wear of the operating 250,000 km mileage is compared and analyzed.The research results show that in the case of new wheels,the stability,comfort and wheel wear of Type A EMUs are better than Type B,but Type A EMUs are greatly affected by wheel wear,resulting in the sharply fallen of operation performance with the increase of operating mileage.Compared with the wheel wear,the wheel wear of Type B EMUs is mainly characterized by wide wear range but less wear depth and more uniform.The wheel wear of Type A EMUs is mainly characterized by narrower wear range and large wear depth,resulting in hollow wear is more obvious.Aiming at the problem of wheel polygonal wear of high-speed EMU vehicles,the factors of the wheel polygonal wear are summarized.The characteristics of wheel polygonal wear of high-speed EMU vehicles are analyzed,and their influence to the running performance of the vehicle is analyzed.The wheel polygonal wear has a great impact on the axlebox and wheelset,especially during high-speed operation.The increase of the wear wave depth and the approach of the frequency of vibration caused by the wheel polygonal wear and the vertical vibration frequency of the sleeper will sharply increase the vibration of the axlebox and wheelset,and let the wheel tread wear worse.According to rail polish to solve the problem of abnormal vibration of the vehicle caused by rail wear.According to the results of the tracking test,the running performance of the vehicle after rail grinding has been significantly improved compared to the rail before grinding.At last,the grinding cycle was estimated based on the characteristics of Wuhan-Guangzhou passenger line and the actual situation.Aiming at the serious side wear of the rail on the small radius curve which running in and out of the railstation,the running performance of curve passing and rail wear under different rail parameters are optimized.Reducing the wheel-rail friction coefficient of high rail,appropriately widening the rail gauge,and adopting the asymmetric rail cant setting of the high and low rail can effectively reduce the side wear of the small radius curve.Based on the optimized curve rail parameters,the line is modified to compare the rail wear before and after optimization.The modified wear depth of high rail is reduced by more than 50%,and the wear area is reduced by more than 40%.It effectively improves the side wear of high rail and controll the corrugation phenomenon on the low rail surface. |
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