基于微观蠕滑饱和的地铁线路钢轨波磨发生概率及发展特征

Rail Corrugation Occurrence Probability and Development Features Under Micro Creep Saturation of Metro Lines

  • 摘要: 聚焦轮轨接触行为,从微观角度研究了地铁线路上钢轨波磨的发生概率和发展特性. 利用车辆−轨道多体动力学数值模型,并结合Modified-Fastsim切向接触算法,提出了蠕滑率饱和临界值用于分析轨面光滑和粗糙条件下不同曲率半径线路上的波磨发生概率. 同时,采用Archard模型计算了轮轨接触斑的平均磨耗深度,进而分析了钢轨波磨的演化特征. 结果显示,内外侧轮轨接触蠕滑在线路曲线半径小于450 m时均趋近于饱和,说明内外侧钢轨均具有发生波磨的可能性,而当线路曲线半径大于450 m时,钢轨波磨发生概率降低. 轨面不平顺的存在能够导致轮轨接触产生反馈振动,从而提高轮轨系统钢轨波磨的发生概率. 随着线路曲线半径的增加,轮轨接触斑平均磨耗深度趋于减小,且平均磨耗深度减小速率表现为先增大后降低,说明曲线半径越小,钢轨波磨磨耗程度越大,磨耗速率越快. 内外侧(左右侧)接触斑的平均磨耗深度变化相似,外侧接触斑的平均磨耗深度在小半径曲线上略高于内侧,表明内外侧(左右侧)钢轨的磨耗程度和磨耗速率基本相似,但考虑到内外侧轮轨接触几何关系有所差异,外轨倾向于轨侧波磨,内轨则主要为轨顶波磨.

     

    Abstract: Focusing on the wheel-rail contact behavior, the occurrence probability and development characteristics of rail corrugation on metro lines were investigated from the micro perspective. Using the numerical model of vehicle-track multi-body dynamics, combined with the tangent contact algorithm Modified-Fastsim, a critical value of creepage saturation was proposed to analyze the occurrence probability of corrugation on the lines with different radii of curvature under conditions of smooth and rough rail surfaces. And the average wear depth of wheel-rail contact patch was calculated simultaneity with the Archard model, further more the evolution features of rail corrugation were analyzed. The results show that the inside and outside wheel-rail contact creepages all tend to be saturated when the curve radius of the line is less than 450 m, all having the corrugation possibility produced on the inner and outer rails. And when the curve radius of the line is more than 450 m, the occurrence probability of the rail corrugation can decrease. On the other hand, the irregularities of rail surface can lead to the feedback vibration in wheel-rail contact, enhancing the occurrence probability of rail corrugation in wheel-rail system. With the increase of the curve radius of the line, the average wear depth of wheel-rail contact patch tends to decrease, and the average wear depth decreases at a rate that increases first and then decreases, meaning that the smaller the curve radius is, the greater the wear degree of rail corrugation is and the faster the wear rate is. The average wear depths of inside and outside (left and right sides) contact patches are similar, and the average wear depth of the outside contact patch is slightly higher than that of the inner side on the small radius curve, demonstrating that the wear degrees and wear rates of inner and outer (left and right sides) rails are basically similar. However, considering the difference between the inside and outside wheel-rail contact geometries, the corrugation of outer rail tends to appear on the rail side, while the corrugation of the inner rail appears mainly on the rail top.

     

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