【作者】 王喆； 赵小罡； 赵鑫； 温泽峰； 金学松；

【Author】 Wang Zhe;Zhao Xiaogang;Zhao Xin;Wen Zefeng;Jin Xuesong;State-key laboratory of Traction Power,Southwest Jiaotong University;

【机构】 西南交通大学牵引动力国家重点实验室；

【摘要】 针对轮轨滚动接触疲劳裂纹扩展的研究,多采用移动载荷法来模拟轮轨滚动接触载荷,忽略或简化了非赫兹接触、高频轮轨相互作用、瞬态滚滑等行为以及裂纹对轮轨滚动行为的影响。本文扩展了之前基于三维轮轨滚动接触有限元模型建立的裂纹瞬态扩展分析模型,引入多条钢轨表面斜裂纹,深入分析了车轮打滑这一极端工况下多条裂纹之间的相互影响,数值重现了300 km/h运行速度下真实的滚动接触载荷条件,突破了以往研究的众多假设前提。结果表明,裂纹会降低轮轨间法向接触刚度,且降低量随裂纹数量的增多而增大,造成行经车轮额外的振动,使得法向轮轨力出现幅值约为0.5 k N的波动;多条裂纹的瞬态裂纹面接触力之间存在重要的不同,尤其是第1和最后一条裂纹的结果往往与其它差异明显;裂纹数量和裂纹间相对位置对裂尖应力强度因子具有显著的影响,但其影响规律有待进一步研究。更多还原

【Abstract】 For study on propagation of wheel/rail rolling contact fatigue(RCF) cracks,the moving Hertzian loading is usually employed to represent the rolling contact loading,and the non-linear wheel-rail contact,high frequency wheel/rail interactions,transient rolling-sliding behavior and the influence of cracks on wheel-rail rolling are all ignored or simplified. This paper extends the previously developed transient wheel-rail rolling contact finite element model for cracking analysis to take into account multiple oblique rail RCF cracks,breaking many assumptions of previous studies. The full sliding between wheel and rail,as an extreme case,is mainly analyzed in this work,and a rolling speed of 300 km/h is simulated. The results have shown that the existence of cracks will reduce the contact stiffness between wheel and rail,resulting in a variation of about 0.5 k N for the vertical wheel-rail contact force. Furthermore,the contact stiffness reduction increases with the number of the simulated cracks. The contact force between crack faces is very different from one crack to another and the results of the first and the last cracks are particularly different from the others. The number of cracks and their relative positions are found to have significant influence on the stress intensity factors,but further study is required to clearly reveal such an influence.更多还原