This study investigated the fretting wear and fatigue of full-scale railway axles. Fatigue tests were conducted on full-scale railway axles, and the fretting wear and fretting fatigue in the fretted zone of the railway axles were analysed. Three-dimensional finite element models were established based on the experimental results. Then, multi-axial fatigue parameters and a linear elastic fracture mechanics-based approach were used to investigate the fretting fatigue crack initiation and propagation, respectively, in which the role of the fretting wear was taken into account. The experimental and simulated results showed that the fretted zone could be divided into zones I–III according to the surface damage morphologies. Fretting wear alleviated the stress concentration near the wheel seat edge and resulted in a new stress concentration near the worn/unworn boundary in zone II, which greatly promoted the fretting crack initiation at the inner side of the fretted zone. Meanwhile, the stress concentration also increased the equivalent stress intensity factor range ΔK_eq below the mating surface, and thus promoted the propagation of fretting fatigue crack. Based on these findings, the effect of the stress redistribution resulting from fretting wear is suggested to be taken into account when evaluating the fretting fatigue in railway axles.

这项研究调查了全尺寸铁路轴的微动磨损和疲劳。在全尺寸铁路轴上进行了疲劳测试，并分析了铁路轴微动区的微动磨损和微动疲劳。根据实验结果建立了三维有限元模型。然后，使用多轴疲劳参数和基于线性弹性断裂力学的方法分别研究了微动疲劳裂纹的萌生和扩展，其中考虑了微动磨损的作用。实验和模拟结果表明，根据表面损伤形态，可将带状区域分为I-III区。微动磨损减轻了轮毂边缘附近的应力集中，并在II区的磨损/未磨损边界附近产生了新的应力集中，这极大地促进了微动区域内侧的微动裂纹萌生。同时，应力集中也增大了等效应力强度因子范围ΔK _eq在配合面以下，因此促进了微动疲劳裂纹的扩展。基于这些发现，建议在评估铁路车轴的微动疲劳时，应考虑到由微动磨损引起的应力重新分布的影响。