一、前言车轴是机车车辆走行装置中最重要而疲劳问题最突出的部件之一。根据调查,当前我国运用车轴中有相当数量存在裂纹,断轴事故屡有发生。运行途中的疲劳切轴往往造成极为严重的后果。车轴疲劳切轴的主要原因是运行中车轴产生了横向裂纹,随着应力循环次数的增加,疲劳裂纹不断扩 I. INTRODUCTION The axle is one of the most important parts of the running gear of rolling stock and the most prominent part of the fatigue problem. According to the investigation, there are a considerable number of cracks in the axle of our country, and accidents of broken shafts happen frequently. Fatigue on the way to cut the axis often results in extremely serious consequences. The main reason that the axis of the axle is tired to cut the axle is that the axle has a horizontal crack in operation. As the number of stress cycles increases, the fatigue crack expands