Longitudinal creep force properties of wheel and rail under short-pitch corrugation state
-
摘要: 为了对具有简谐波形的钢轨短波波磨进行分组与分析轮轨非稳态滚动接触的纵向蠕滑力特性, 引入了波磨深度指数与波长比, 采用Kalker三维滚动接触理论计算了车轮的纵向蠕滑力, 并与采用稳态滚动理论计算结果进行了对比, 使用频率响应的系统辨识法对纵向蠕滑力的波动分量进行了拟合, 在短波波磨等深度指数条件下, 用波长比的二阶传递函数描述了轮轨纵向蠕滑力的波动分量与稳态理论波动分量之间的关系, 使用传递函数, 由稳态纵向蠕滑力的波动分量计算了非稳态纵向蠕滑力的波动分量, 进而计算了非稳态的纵向蠕滑力。计算结果表明: 在小蠕滑条件下, 由Kalker三维滚动接触理论计算出的纵向蠕滑力的波动分量随着波长比的变化产生明显的幅值衰减和相位滞后, 波长比越大, 幅值衰减越大, 相位滞后越多, 而稳态滚动理论的计算结果与波长比无关。由传递函数和Kalker数值理论计算的纵向蠕滑力的时域波形、频域幅值谱和相位谱相同。Abstract: Shallowness factor and wavelength ratio were induced to group sinusoidal short-pitch corrugations with simple harmonic waveforms and to analyze the properties of longitudinal wheel/rail creep forces for unsteady state rolling contact, the longitudinal creep forces due to sinusoidal short-pitch corrugations were calculated by Kalker 3D rolling contact theory, and the calculation result was compared with the calculation result from steady rolling contact theory. The system identification method of frequency response was used to fit the fluctuating part of unsteady longitudinal creep force. The relationship of fluctuating parts for unsteady state and steady state longitudinal creep forces was described as two order transfer function of wavelength ratio when sinusoidal short-pitch corrugations had same shallowness factor. The fluctuating part of unsteady longitudinal creep force was calculated according to the fluctuating part of steady longitudinal creep force, thereout, the unsteady longitudinal creep force was calculated. Calculation result shows that under small creep condition, the fluctuating part of unsteady longitudinal creep force decreases in amplitude and phase lag with the growth of wavelength ratio. The bigger wavelength ratio is, the smaller amplitude is, and the more phase lag is. However, the result from steady state theory is independent of wavelength ratio. For unsteady longitudinal creep forces calculated by the transfer function and Kalker 3D rolling contact theory, the waveforms in time domain, the amplitudes and phase spectrums in frequency domain are accordant.
-
表 1 轮轨参数
Table 1. Wheel and rail parameters
表 2 传递函数H的系数
Table 2. Parameters of transfer function H
-
[1] GRASSIE S L, KALOUSEKJ. Rail corrugation: characteristics, causes and treat ments[J]. Proceedings of the Institution of Mechanical Engineers, Part F: Journal of Rail and Rapid Transit, 1993, 207(1): 57-68. doi: 10.1243/PIME_PROC_1993_207_227_02 [2] 温泽峰. 钢轨波浪形磨损研究[D]. 成都: 西南交通大学, 2006.WEN Ze-feng. Study on rail corrugation[D]. Chengdu: Southwest Jiaotong University, 2006. (in Chinese) [3] MÜLLER S. Alinear wheel-track model to predict instability and short pitch corrugation[J]. Journal of Sound and Vibration, 1999, 227(5): 899-913. doi: 10.1006/jsvi.1999.2981 [4] HEMPELMANN K, KNOTHE K. An extended linear model for the prediction of short pitch corrugation[J]. Wear, 1996, 191(1/2): 161-169. [5] XIE GANG, IWNICKI S D. Calculation of wear on a corrugated rail using a three-dimensional contact model[J]. Wear, 2008, 265(9/10): 1238-1246. [6] XIE GANG, IWNICKI S D. Simulations of roughness growth on rails-results from non-Hertzain, non-steady contact model[J]. Vehicle System Dynamics, 2008, 46(1/2): 117-128. [7] KNOTHE K, GROSS-THEBING A. Short wavelength rai lcorrugation and non-steady-state contact mechanics[J]. Vehicle System Dynamics, 2008, 46(1/2): 49-66. [8] KALKER J J. Transient phenomena in two elastic cylindersrolling over each other with dry friction[J]. Journal of Applied Mechanics, 1970, 37(3): 677-688. doi: 10.1115/1.3408597 [9] KNOTHE K, GROSS-THEBING A. Derivation of frequency dependent creep coefficients based on an elastic half-space model[J]. Vehicle System Dynamics, 1986, 15(3): 133-153. doi: 10.1080/00423118608968848 [10] GROSS-T HEBING A. Frequency-dependent creep coefficients for three-dimensional rolling contact problem[J]. Vehicle System Dynamics, 1989, 18(6): 359-374. doi: 10.1080/00423118908968927 [11] ALONSO A, GIM? NEZ J. Non-steady state modelling of wheel-rail contact problem for the dynamic simulation of railway vehicles[J]. Vehicle System Dynamics, 2008, 46(3): 179-196. doi: 10.1080/00423110701248011 [12] PIOTROWSKI J, KALKER J J. A non-linear mathematical model for finite, periodic rail corrugations[C]∥ALIABALI M H, BREBBIA C A. The First International Conference on Contact Mechanics. Southampton: Computational Mechanics Inc., 1993: 413-424. [13] KALKER J J. Three-Dimension Elastic Bodies in Rolling contact[M]. Dordrecht: Kluwer Academic Publishers, 1990. [14] SHEN Z Y, HEDRICK J K, ELKINS J. A comparison of alternative creep force models for rail vehicle dynamic analysis[J]. Vehicle System Dynamics, 1983, 12(1): 70-82. [15] 潘立登, 潘仰东. 系统辨识与建模[M]. 北京: 化学工业出版社, 2004.PAN Li-deng, PAN Yang-dong. System Identification and Modelling[M]. Beijing: Chemical Industry Press, 2004. (in Chinese)