关键词: 低周疲劳;疲劳裂纹扩展;裂纹尖端;应力应变场;应变能;金属

Abstract: Most engineering fracture is caused by fatigue, so the low cyclic fatigue and the crack growth properties are always concerned about the safety design department. For years, the relationship between the low cyclic fatigue and the fatigue crack growth is developed by domestic and foreign scholars from multi-material and multi-angle. A series of prediction models for mode-I fatigue crack growth are proposed with considering the small scale yield of plane stress crack tip condition and the failure criteria of fatigue crack tip. In present study, a prediction model for mode-I fatigue crack growth is proposed based on the small scale yield of plane stress crack tip and the strain energy failure criteria of cyclic plastic zone of fatigue crack tip. With the low cyclic fatigue and the fatigue crack growth for fifteen kinds of metals published in literatures, the proposed prediction model and the six kinds of prediction models are detailed analyzed and compared in the prediction law and results. Research shows that the proposed prediction model can be used to predict fatigue cracking for a wide range of metals and obey the safety design conception than other six kinds of prediction models.

Key words: low cycle fatigue(LCF);fatigue crack growth(FCG);crack tip;stress-strain field;strain energy;metal