摘要
利用WR-1轮轨滚动磨损试验机,结合安定极限理论研究了干态下影响车轮材料表面疲劳裂纹萌生与扩展的因素,探究了表面疲劳损伤形成机理和演变规律.结果表明:随垂向力、横向力和冲角增大,表面疲劳裂纹越容易萌生扩展;冲角对表面疲劳裂纹的萌生与扩展起着重要作用,大冲角下斜线状表面疲劳裂纹萌生扩展明显;只有横向力而不存在冲角时,试样表面不会出现斜线状表面疲劳损伤;车轮试样在周期性循环载荷作用下在表面先形成塑性流动,然后沿轮轨表面切向力方向扩展成斜线状的表面疲劳起皮剥落损伤;垂向力是影响表面裂纹萌生时间的重要因素之一.
The factors affected the initiation and propagation of surface fatigue crack of wheel under dry conditions were investigated and the formation mechanism and evolvement law of surface fatigue damage of wheel were analyzed using a WR-1 wheel/rail rolling wear testing apparatus, combined with the shakedown theory. The results show that with the increase of the vertical force, lateral force and attack angle, initiation and propagation of surface fatigue crack of wheel became more easily. Attack angle played an important role on the initiation and propagation of surface fatigue crack of wheel. Macroscopic oblique surface fatigue crack initiated and propagated obviously under the high attack angle conditions. Surface fatigue damage of wheel was not found in case of only the lateral force but no attack angle. Under cyclic periodic load, plastic flow was observed first on the surface of wheel. And then, propagation to oblique surface fatigue crack along the direction of the shear force on wheel/rail surface was observed. The vertical force was one of the important factors affecting the time of crack initiation.
出处
《摩擦学学报》
EI
CAS
CSCD
北大核心
2016年第2期194-200,共7页
Tribology
基金
国家自然科学基金项目(51475393
U1134202)资助~~
关键词
车轮材料
安定理论
表面疲劳裂纹
萌生
冲角
wheel material
shakedown theory
surface fatigue crack
initiation
attack angle
