轧机油膜轴承锥套接触疲劳损伤的机理分析

Analysis of Contact Fatigue Damage Mechanism for Sleeve of Oil-film Bearing in Rolling Mill

研究了油膜轴承锥套与辊颈接触表面在轧制载荷作用下发生微动疲劳损伤的力学机理。在分析油膜轴承油膜压力分布特征的基础上,采用有限元法给出了锥套与辊颈接触区边缘产生接触应力集中和微滑移的分布规律,阐明了弹性结合连接的锥套与辊颈接触表面产生微动疲劳损伤的原因。利用断裂力学裂纹尖端应力场与接触边缘区域应力局部渐近场的等效原则,给出了疲劳裂纹自点蚀处萌生与扩展的力学条件。上述结果为锥套和辊颈的实际损伤状态及模拟试验所验证。

This paper presented the mechanism of fretting fatigue failure that happened on the contact surfaces between sleeve and roll neck of oil-film bearing under the rolling load. Based on the analysis of distribution characteristics of the oil- film pressure, the contact stress concentration and the micro-slip distribution regularity at the edge of the contact zone were given by the finite element method, and the reasons for the fretting fatigue failure developed on the contact surfaces between sleeve and roll neck with interference fit were illustrated. By an equivalent principle of the local stress fields derived from the classical analysis for sharp-edged contact problem and the crack-tip fields obtained according to the fracture mechanics methods, the mechanics condition of the fatigue crack initiation and propagation occurred from the corrosive pitting was analyzed. The result was also certified by the practical damage state and simulation test.