等效锥度非线性研究及其在踏面设计中的应用

Research on nonlinear characteristics of equivalent conicity and its application in wheel tread profile design

为研究等效锥度非线性特性对车辆系统动力学和磨耗性能的影响,提出可以用于踏面优化设计的非线性特性建议指标。通过对轮轨关系进行细致推导,应用踏面逆向设计快速递推算法,得到具有不同等效锥度非线性特性的踏面,对不同踏面的轮轨关系进行分析。建立车辆系统动力学模型和基于Archard理论的磨耗预测模型,对不同非线性特性踏面的临界速度、横向平稳性、磨耗性能进行对比分析。研究结果表明:非线性因子值过高或过低都会导致临界速度下降,但该指标过高对临界速度影响更大,最大降幅可达20%;等效锥度非线性特性还会影响到踏面的磨耗发展,踏面的初始非线性因子越高,名义等效锥度在磨耗过程中的增长越慢,对延长车轮服役周期是有利的。综合动力学性能及磨耗性能,建议高速列车踏面的非线性因子应取尽可能接近于0的负值。在这一结论的指导下,对S1002CN踏面进行优化设计,得到名义等效锥度为0.1,等效锥度非线性因子为0.013(与S1002CN持平)、-0.002的优化踏面S1002CN_opt1、S1002CN_opt2,优化踏面S1002CN_opt2与S1002CN相比临界速度和横向平稳性有所优化,同时磨耗性能也有所提升。S1002CN_opt2与S1002CN_opt1之间的等效锥度非线性关系在动力学性能及磨耗性能中的表现证明以等效锥度非线性因子限值指导踏面进行优化设计的可行性,研究结果可为踏面设计及轮轨关系研究提供参考。

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.