Influence Of Wheel Concave Wear On Vehicle Dynamic Performance

High-speed railway has strong transportation capacity,fast speed,good safety and environmental protection.It is a transportation mode with obvious technical and economic advantages.However,with the continuous improvement of train running speed,the requirements for wheel-rail matching performance are becoming more and more strict.The tread wear will change the wheel-rail contact state and affect the running quality of the vehicle,especially the concave wear has a great influence on the surface damage of the wheel and rail.Therefore,it is necessary to study the influence of the concave wear of the wheel on the dynamic performance of the vehicle,which is beneficial to improve the economic and social benefits of railway transportation.In this paper,by obtaining the tread profile under different operating mileages during the re-profile period of the on-site measurement,the existing data is analyzed and screened,and five sets of wheel profiles are determined as research objects.and the wheel-rail contact geometry analysis is carried out.analyzes the straight dynamic performance and the curve passing ability of the vehicle respectively.The curve analysis analyzes the two modes of the track without track excitation and the track with track excitation.The dynamics is combined with the wheel-rail contact analysis to comprehensively analyze the relationship between the concave wear and the dynamic characteristics of the vehicle.The results show that:After the wear,the wheel-rail contact point jumps,the wheel-to-rolling circle radius difference and the equivalent taper increase,and the wheel-rail matching performance decreases.When the vehicle is running in a straight line,the concave wear reduces the critical speed of the vehicle,reduces the amplitude of the wheel traverse,but increases the probability of a large displacement of the wheel pair.The lateral stability gradually deteriorates with the increase of wear and has little effect on the vertical stability.When the concave wear depth reaches 0.9 mm,the lateral force and lateral vibration acceleration of the wheel and rail increase greatly.When the wear depth reaches 1.5?1.8mm,the lateral acceleration amplitude of the frame has reached the critical value of 8 m/s2,which poses a safety hazard.The tread should be re-profiled.When the vehicle passes the 800m radius curve,there are some differences in the change rules of the front and rear wheel pairs of the bogie.With the increase of the wear,the dynamic performance of the front wheel pair is improved,the passing ability of the rear wheel is reduced,there are similar changes in the indicators of the excitation curve and the non-excitation curve.When the vehicle passes the 7000m radius curve,the vehicle curve passing ability is reduced,and the indexes of the front wheel pair of the bogie are better than the rear wheel pairs,there are some differences between the parameters of the excitation curve and the non-excitation curve.Therefore,the concave wear causes the lateral force of the wheel and rail to increase,the wheel-rail impact is intensified.It causes the lateral acceleration of the frame increases and exceeds the limit,which is an important factor affecting the re-profile cycle.