Analysis Of Wheel/Rail Profile Optimization Of High Speed Railway To Improve Wheel-rail Matching Performance

With the continuous increase of vehicle speed,the wheel-rail relationship,which is one of the basic problems of the vehicle-rail system dynamics,becomes more and more important.The mechanism of the wheel-rail contact relationship is becoming more and more complicated,and the interaction between the wheel and the rail increases.This will inevitably result.Directly affect the stability and safety of driving.Good wheel-rail profile matching can achieve ideal vehicle performance including derailment safety,curve passing performance,operational safety and stability.In order to obtain good dynamic performance,to improve the wheel-rail interaction force and the wheel-rail contact state,it is necessary to optimize the more matching wheel profile according to the existing line.At present,China's high-speed railway mainly uses 60 kg/m rails.In order to compare the matching performance of CHN60,60N rails and LM_A wheel profile,a geometric parameter model of wheel-rail contact and a dynamic model are established.The results show that the contact point distribution is more concentrated and the equivalent taper is smaller when LM_A matches 60N in the wheel-rail contact geometry.In terms of linear running stability,LM_A matches 60N with higher critical speed,better lateral stability of the vehicle,and other indicators have less difference.In terms of curve passing capability,the wear power is smaller when matched with CHN60,and other indicators have less difference.Therefore,the rolling radius difference when LM_A matches 60N should be the design goal,and the wheel profile that is more compatible with the CHN60 should be optimized.The rolling radius difference is one of the main parameters that determine the dynamic performance of the vehicle,which determines the kinematics and dynamic performance of the wheelset.According to the geometric characteristics of wheel-rail contact,a method of reverse design of wheel-rail profile is presented.The method includes three parts:wheel profile design,symmetrical rail profile design and asymmetrical rail profile design.It uses the rolling radius difference as the goal.Based on the rail profile(wheel profile)and the rolling radius difference curve,the dichotomy,slope control method and the numerical method of the cycle iteration are used to obtain the wheel profile(rail profile)that meet the design requirements,and the corresponding program is developed.At the same time,the verification of the wheel-rail profile design method was carried out,and the validity of the design method was verified through the reverse design of the wheel profile,symmetrical rail profile and asymmetric rail profile.Taking the CHN60 rail as the object,the rolling radius difference when LM_A matches60N is the design goal,and the wheel profile is optimized.The optimized wheel profile has more reasonable contact stress,critical speed increased by 10.8%,vehicle lateral stability increased by about 7%.When passing the curve,the wheel friction power,derailment coefficient,and wheel-rail lateral force are all reduced except for a slightly larger amount of wheel-slide.When passing the curve,the wheel friction power,the deration coefficient and the transverse force of the wheel and rail are all reduced except for the amount of wheel lateral movement.