Influence Of Wheel Diameter Difference On The Dynamic Performance Of Vehicles And Analysis On Wheel Wear In The Process Of Vehicle-bridge Coupling

With the increase of train speed and axle load, the condition of the wheel-railcontact is increasingly complex, and the influence of the widespread wheel diameterdifference and wheel wear, which have mutual malignant influence on each other, onthe dynamic performance of bridge and vehicle systems are more remarkable inmodern train system, which seriously affect the safety and stability of train operationand worsen the load status of bridge. Therefore influence of wheel diameter differenceon the dynamic performance of bridge and vehicle systems and wheel wearmechanism in the process of vehicle-bridge coupling are advanced subject concernedextensively, and deeply studying on them is practical. Main research works aiming atthe problems are as follows:1. The influence of the four most common wheel diameter differences on thedynamic performance of vehicle system was researched, which takes into account thechanges of tread taper of wheel in bogie with wheel diameter difference, and thedifferentiation between the influence laws and the reasons of each influence law areanalyzed. The simulation results are obtained: all of the four most common wheeldiameter differences affect the safety and stability of train operation, and the dynamicperformance of vehicle system is getting worse with the increase of wheel diameterdifference.2. The calculating equation of the wheel-rail relative sliding velocity, which takesinto account the slippage of rigidity and the elastic deformation in the contact patchand makes the simulation results of wheel wear more precise, is derived by using theparameters being taken from the process of solving wheel-rail contact lateral force.The question of without considering the influence of the elastic deformation in thecontact patch to analyze the wheel wear is resolved.3. On the base of vehicle-bridge coupling vibration theory, a simulation programto predict the railway wheel wear in the process of vehicle-bridge coupling iscompiled by applying the software of Visual Fortran. The influence of four typicalwheel diameter difference on wheel wear are analyzed, and the results indicate thatwheel diameter difference not only results in the wheel eccentric wear, but also causes the changes of the wear area of wheel tread. And the influence of train speed, materialhardness of the wheel, superelevation and curve radius on the wheel wear wereanalyzed. Analysis result shows that wheel wear rises as train speed increases, andwith the increase of material hardness of the wheel, superelevation and curve radius,wheel wear decreases.