Study On The Wear Of Metro Wheels And Its Profile Optimization

In recent years,with the large-scale construction and operation of urban rail transit in China,the problem of wheel wear has become more and more prominent,which has affected the safety of train operation and passenger ride comfort.The wheel replacement and repair caused by the rapid wear of the wheels also brought huge Economic loss.Therefore,in order to alleviate the wheel and rail wear problem,the subway wheel profile is optimized for the existing wheel-rail system structure and operating environment.In this paper,the three-NURBS curve is used to construct the wheel profile geometry,and the low-wear wheel profile optimization design model is designed.Integrating with the vehicle dynamics model,the joint optimization particle swarm optimization algorithm solves the wheel profile optimization model multiple times and obtains the optimized wheel profile.After that,the optimized profile and the standard profile were compared to verify the dynamic performance and wear.The results show that:(1)Through the static contact analysis of the standard wheel profile LM and the optimized design profile LM-OPTI and CHN60 rails,the LM-OPTI profile has less contact with the rim and the rail side than the LM profile.This change is beneficial for reducing rim wear and orbital side grinding;LM-OPTI/CHN60 matching with respect to LM/CHN60 matching,equivalent taper,rolling circle radius difference,contact angle difference and contact point radius are reduced.(2)The kinetic calculations of the LM and LM-OPTI wheel profiles and the new rails and the measured wear rails are carried out.The comparison between the two profiles is carried out under different curve radii and different running speeds under the new rail and wear rail matching conditions.Stability,smooth running,and curve pass safety parameters.It is analyzed that the optimized profile has a certain optimization ratio in terms of vehicle running stability and running stability compared with the standard profile;the wheel-rail lateral force and the derailment coefficient have a large optimization ratio in terms of the safety of the curve;the wheel-rail vertical force The performance of the two profiles with the wheel load shedding rate is not much different;and all the indicators are in line with China's current standards.At a speed of 50km/h,the wheel and the wear rail match the maximum lateral force of the wheel rail with a maximum optimized ratio of 28.31%.(3)Through the simulation analysis of the combination of multi-curve and straight line,the kinetic values of the optimized wheel profile are reduced to different degrees with respect to the standard wheel profile.The Optimum Ratio of the lateral vibration acceleration of the frame is the largest,which is 20.97%.The wheel-rail vertical force RMS optimization ratio is the smallest,which is 0.71%.(4)For the wear prediction analysis of the LM wheel profile and the LM-OPTI wheel profile matched with the new rail and the wear rail,respectively,it can be concluded that the optimized profile has a significant reduction in wear compared to the standard profile rim.Small,the tread wear has increased.In general,the optimized wheel surface wear is less than the standard surface wear.(5)Through the finite element analysis of the two-face wheel,the stress at the LM-OPTI wheel profile rim is lower than that of the LM standard wheel profile,and does not exceed the elastic limit of the wheel material.Through the analysis of the wheel-rail contact analysis,during the change of the traverse amount from 0mm to 5mm,the LM-type wheel has two-point contact,and the LM-OPTI-type surface has no two-point contact.