车轮踏面凹型磨耗特征参数及其影响分析

Analysis of Characteristic Parameters of Wheel Tread Concave Wear and Their Effects

摘要: 基于车轮踏面凹型磨耗统计数据，分析其几何分布特征。采用非均匀有理B样条(NURBS)曲线理论，对车轮踏面凹型磨耗廓形进行参数化拟合并开展验证分析，选取磨耗区域内关键控制点及权因子作为凹型磨耗的参数化表征变量。同时，建立考虑车轮踏面凹型磨耗的车辆系统动力学模型，分析不同凹型磨耗参数化变量对轮轨接触特性及车辆动力学性能的影响。结果表明：凹型磨耗主要集中于踏面中部区域，在名义滚动圆附近呈局部下凹且整体连续光顺的几何特征；基于NURBS的参数化方法能够较好拟合不同工况下的磨耗廓形，并获得磨耗区域关键控制点及权因子等参数化表征结果；在本文所设定的参数范围和工况条件下，控制点横坐标变化相较于其纵坐标和权因子，对接触应力分布以及轮轨横向力、轴箱横向加速度与脱轨系数的影响更为明显，而权因子的影响相对较弱，但在局部区间存在一定非单调变化。

Abstract: Based on statistical data of wheel tread concave wear, the geometric distribution characteristics were analyzed. Non-Uniform Rational B-Spline (NURBS) curve theory was adopted to perform the parametric fitting and validation of wheel tread concave wear profiles, and key control points and weight factors within the wear region were selected as parametric characterization variables for concave wear. In addition, a vehicle system dynamics model considering wheel tread concave wear was established to investigate the effects of different parametric variables on wheel–rail contact characteristics and vehicle dynamic performance. The results indicate that concave wear is mainly concentrated in the middle region of the tread, showing a locally depressed geometric feature near the nominal rolling circle while maintaining overall continuity and smoothness. The NURBS-based parametric method can accurately fit wear profiles under different operating conditions and obtain parametric characterization results, such as key control points and weight factors, for the wear region. Under the parameter ranges and operating conditions considered in this study, variations in the horizontal coordinates of the control points have more pronounced effects on wheel–rail contact point migration, contact stress distribution, wheel–rail lateral force, axle-box lateral acceleration, and derailment coefficient than variations in the vertical coordinates and weight factors. The influence of the weight factors is relatively weak, although certain local intervals exhibit non-monotonic variations.