简析高速重载工况对车轮轮辋疲劳裂纹萌生的影响

Effect of Fatigue Crack Initiation in Wheel Rims under Condition of Heavy Haul and High Speed

研究了在重载列车和高速列车车轮实际使用工况下,轮轨接触应力提高后车轮轮辋内部应力增加对轮辋疲劳裂纹萌生的影响。对普通列车、重载列车、高速列车上实际运用过程中发生辋裂的车轮进行失效分析和研究,结果表明:列车轴重增加和运行速度提高,导致车轮轮辋内部萌生裂纹的"临界夹杂物尺寸"减小,使车轮轮辋中原本处于安全尺寸范围的脆性夹杂物越过"临界夹杂物尺寸"成为疲劳裂纹萌生的主要发源点,最终导致车轮轮辋疲劳裂纹的形成。

Effect of the increase of interior stresses in wheel rim due to the increase of wheel/rail contact stresses on the fatigue crack initiation in rims has been studied for actual service conditions of heavy haul and high speed train wheels. The results obtained from the analysis of three different failure wheels which are typical fatigue crack in rims show that the critical inclusion sizes of non--metallic inclusions which cause crack initiation in wheel rims are decreased with increasing axle load and speed of trains. It is also demonstrated that the previous brittle inclusions with safety sizes have been reached the critical inclusion sizes and become the main source of fatigue crack initation in wheel rims resulting in the fatigue crack initiation.