两种型面轮轨滚动接触蠕滑率/力的比较
CREEPAGES AND CREEP FORCES OF WHEELSET AND TRACK WITH TWO TYPES OF PROFILES IN ROLLING CONTACT
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摘要: 本文从数值方面详细分析了两种型面轮对和轨道在滚动接触过程的接触几何、蠕滑率和蠕滑力.在利用Kalker三维弹性体非赫兹滚动接触理论进行轮轨蠕滑力分析时,首先利用有限元方法确定了因轮轨的弹性变形而引起轮轨接触点处的弹性位移差.并利用弹性位移差修正Kalker理论中由Boussinesq和Cerruti公式确定的力和位移的影响系数,使本文的数值过程能考虑到轮轨结构变形对轮轨接触斑的影响.通过计算分析可知,在轮对运动状态相同的情况下,磨耗型轮对和轨道之间的力学行为与锥型轮对和轨道之间的力学行为相比,存在较大差异.数值结果有助于进一步分析轮轨之间的磨耗、滚动接触疲劳和轮轨使用寿命,为采取相应措施提供理论依据.同时发现目前我国铁路所采用的1/40轨底坡与目前正在全面推广使用的磨耗型轮对不是处于最佳匹配状态,有待进一步改进.Abstract: The contact geometry, creepages and creep forces of wheelset/track with two types of wheel profiles in rolling contact are investigated with numerical methods. In the analysis of the creep forces with Kalker theory of three-dimensional elastic bodies in rolling contact with non-Hertzian form, finite element method is first employed to determine differences of elastic displacement of wheel/rail at the contact point. The differences of elastic displacement of wheel/rail are caused by elastic deformations of wheelset/track. Therefore, they are used to revise the influence coefficients obtained with the formula of Boussinesq and Cerruti in Kalker's theory, so that the effects of the structural elastic deformations are taken into account in the analysis of the present paper. Numerical results indicate that the action behavior between a wheelset with worn profile and track is greatly different from that of wheelset with coned profile and track under the same moving condition of wheelset. The present results are very useful in further study on wear, rolling contact fatigue and service life of wheel/rail since they can provide theoretical basis for adopting corresponding measures to protect wheel/rail from failure. It is also found that rails with cant angle of 1/40 do not match a wheelset with worn profile very well. So the profile of wheelset with worn profile that is widely used in railway field at present and the existing cant angle of rails need to be further improved.