A numerical optimization technique for design of wheel profiles
A numerical optimization technique for design of wheel profiles
复制标题
DOI：
10.1016/j.wear.2006.06.006
复制
发表时间：
2008-01
期刊：
影响因子：
5
通讯作者：
H. Jahed;B. Farshi;M. A. Eshraghi;A. Nasr
中科院分区：
文献类型：
--
作者：
H. Jahed;B. Farshi;M. A. Eshraghi;A. Nasr
本文提出了一种用数值优化方法确定给定轮轨几何接触特性的最佳车轮外形的方法。这些特性通过给定的钢轨轮廓和作为横向位移（Y）的函数的目标滚动半径差（Δr）来定义。利用三次样条函数连接轮廓曲线段，使轮廓曲线具有平滑的变化趋势。低次多项式的系数可以表示曲线的广义坐标。以这种方式，所需坐标的数量大大减少。结果表明，设计变量的总数只有五个，这使得计算优化过程非常有效。在非梯度数值优化程序中，采用复合形算法生成一系列改进型面，最终得到最优型面。然后利用亚当斯/Rail软件包获得其Y-Δr曲线，确定所生成的轮廓的动力学性能。目标是在给定的车辆和轨道特性下，最大限度地减少所生成的剖面的Y−Δr性能与目标剖面的偏差。随后，所提出的方法是用来设计一个车轮的客运车辆，符合伊朗东北部铁路的特点。并与S1002和P8标准型材的动态性能进行了比较。结果表明，所设计的齿廓的磨损指数明显低于其它两种齿廓。此外，其他动态特性，如横向位移，攻角和脱轨商显着改善。该程序有效地工作，结果证明是相当令人满意的。
A method for determination of an optimum railway vehicle wheel profile for a given geometric contact characteristics of wheel/rail using a numerical optimization approach is presented in this paper. Such characteristics are defined through a given rail profile, and the target rolling radii difference (Δr) as a function of lateral displacements (Y). Cubic spline functions are utilized to connect curve segments of wheel profile to produce smooth variation trends desired. The coefficients of low degree polynomials could represent the curve's generalized coordinates. In this manner the number of necessary coordinates is greatly reduced. It is shown that the total number of design variables is only five, which computationally makes the optimization process very efficient. The method of Complex algorithm within the non-gradient numerical optimization routines is selected to generate a sequence of improving profiles leading to the optimum one. Dynamic performances of the generated profiles are then determined by obtaining their Y−Δr curves using ADAMS/Rail software package. The objective is to minimize the deviation of the Y−Δr performances of the generated profiles from the target one, under the given vehicle and track characteristics. Subsequently, the proposed method is used to design a wheel profile for passenger vehicles, compatible with the Iranian north-eastern railway characteristics. The dynamic performances of the designed profile, and those of S1002 and P8 standard profiles, are presented for comparison. It is shown that the wear index of the designed profile is significantly lower than the other two. In addition, other dynamic characteristics such as lateral displacement, angle of attack and derailment quotient are shown to be improved considerably. The procedure worked efficiently and the results proved to be quite satisfactory.