材料的疲劳过程是能量耗散的过程,它在宏观上表现为热耗散。能量理论是研究材料疲劳行为的微观机理和宏观现象的桥梁。利用具有准确、快速、便捷、低成本等优点的红外热像仪测量了45# 钢疲劳过程中的温度变化,并对疲劳过程中引起温升的机制进行了探讨。通过对试验数据的分析,快速确定了45# 钢的疲劳极限,而且实测值处于疲劳极限估算值的范围内。

The fatigue process of a rnaterial is an energy dissipation process. It is presented as heat dissipation rnacroscopically. The energy theory is a bridge to study the rnicroscopic rnechanisrn and rnacro scopic phenornenon of the fatigue process of a rnaterial. An accurate, fast, easy-operated and low-cost infrared therrnographer is used to rneasure the ternperature variation in the fatigue process of 45# steel The rnechanisrn resulting in ternperature rise in the fatigue process is discussed. Through analysis of the measured data, the fatigue lirnit of the 45# steel is deterrnined quickly. It is shown that the rneasured fatigue lirnit is within the estirnated fatigue lirnit range.