Dynamic Performance Analysis Of Matching Of Wheel And The Switch Rail

With the rapid development of railway transportation at home and abroad,the transporting task of heavy-haul railways has become increasingly onerous,and the wheel-rail matching contact and wear have become a major concern.Due to the weak tip and variable cross-section structure of the switch rail,the wheel-rail matching and dynamic effect on the switch rail is more complicated.Switch rail is one of the track parts which are damaged and worn easily.Because the locomotive is at the front of the train,the interaction between the wheel and the switch rail is more intense when passing the switch proper of turnout.In the actual production and application process,non-standard conditions occur on the wheels and rails,such as the wheel diameter difference,wheelset deflection angle and the height difference between the switch rail and stock rail,which could further affect the wheel-rail matching state.Therefore,it is of great significance to study on the dynamic performance of wheel and switch rail under different working conditions.Based on the theory of multi-body system dynamics,the coupling dynamic models of locomotive-switch rail are established by using SIMPACK software to simulate and calculate the matching of wheel and switch rail under different working conditions The dynamic performance of wheel and the switch rail with the standard,different wheel diameter difference,wheelset deflection angle or the height difference are analyzed.The present paper conducts the following work:(1)The standard JM3 wheels were matched with standard 75 kg/m rail and the switch rail respectively,and the wheel-rail contact state,running stability,running safety and the wheel's dynamic effect on the rail were analyzed.Lateral and vertical impact vibration occurs when the locomotive enters the switch area,resulting in an increasing wheel-rail dynamic effect,which is particularly noticeable when the locomotive is driven from the curved switch rail to the straight stock rail.It not only affects the safety and stability of the locomotive operation,but also aggravates the wheel-rail wear.(2)Aiming at the problem of wheel diameter difference,the coupling dynamic models of locomotive-switch rail with different wheel diameter were established.And the dynamic performance of locomotives through the straight and curved switch rail was analyzed from both theoretical and simulation calculations The results show that the wheel diameter difference has a great impact on the lateral dynamic action between the locomotive and track,and the lateral vibration energy of the car body increases sharply as the locomotive passes through the curved switch.With the increase of wheel diameter difference,the overall wear of wheels and switch rail tends to increase,and the phenomenon of partial wear becomes more serious.(3)Considering the wheelset deflection angle,the locomotive models with single wheelset deflection angle,front and rear wheelset deflection angles,bogie deflection angle and vehicle deflection angle were established respectively to calculate and analyze the dynamic performance of wheels through the switch rail.The existence of wheelset deflection angle leads to the change of contact state and interaction force between wheel and rail,which increases the possibility of derailment.With the increase of wheelset deflection angle,the adverse effects become more and more serious,which seriously endangers the running safety of locomotive.(4)The height difference was adjusted to generate different profiles of the switch rail.The dynamic models of locomotive-straight switch rail and locomotive-curved switch rail were established to analyze the influence of the rail height difference on the dynamic performance when locomotive passes through the switch rail.As the height difference of the switch rail deviates from the standard value,the transition position of the wheel load changes.When the height difference of the switch rail is greater than the standard value,the derailment coefficient,the wheel unloading rate and the lateral wheel-rail force all significantly increase,which deteriorate the matching performance of wheel and switch rail.