Research on nonlinear characteristics of equivalent conicity and its application in wheel tread profile design
To delve into the influences of equivalent conicity nonlinear characteristics on the dynamics and anti-wear performance of vehicle systems,the suggested nonlinear characteristics metrics that can be used for the optimal design of the wheel tread were presented.Through meticulous deduction of the wheel-rail relationship and the application of reverse design methodology for the wheel profile,a fast recursive algorithm was utilized to obtain tread profiles with varying nonlinear characteristics of equivalent conicity.The analysis was then conducted on the wheel-rail relationship for different wheel profiles.A vehicle system dynamics model and a wear prediction model based on the Archard theory were established to compare and analyze the critical speed,lateral smoothness,and wear performance of these wheel profiles.The research results show that both excessively high and low values of the nonlinear factor will cause a decrease in critical speed,but the impact of excessively high values on the critical speed is greater,with a maximum reduction of up to 20%.The equivalent conicity nonlinear characteristics also affect the wear development of the wheel.The higher the tread's initial nonlinear factor,the slower the nominal equivalent conicity of the wheel would increase during the wear process,which is beneficial for extending the service life of the wheel.Considering the comprehensive dynamic and wear performance,it is recommended to choose a negative value as close to zero as possible for the initial wheel nonlinear factor of high-speed trains.Following this conclusion,the optimization design of the wheel profile of the S1002CN was carried out,resulting in two optimized wheels,namely S1002CN_opt1 and S1002CN_opt2,with a nominal equivalent conicity of 0.1 and nonlinear factors of 0.013(consistent with S1002CN)and-0.002,respectively.Compared to S1002CN,S1002CN_opt2 shows improvements in critical speed,lateral smoothness,and wear performance.The performance of the equivalent conicity nonlinearity between S1002CN_opt2 and S1002CN_opt1 in dynamic and wear properties demonstrates that utilizing the limitation of the equivalent conicity non-linear factor to guide the optimization design of the wheel profile is highly feasible.The research results can provide reference for wheel tread design and wheel-rail relationship studies.
equivalent conicity nonlinearityreverse design of wheel profilevehicle system dynamicswheel-rail contact relationshipwheel wear