缺口小裂纹的疲劳扩展速率

On the Short Fatigue Crack Propagation Rate at Notch

将复型技术应用于疲劳小裂纹扩展试验中的裂纹长度测量。在等载荷比R=0.1、不同平均载荷水平影响的疲劳条件下,板试样V型缺口小裂纹疲劳扩展速率做了试验测试;通过结果分析,提出了缺口小裂纹疲劳扩展速率表达式,并以εp为控制参数,求出45~#钢的计算式。

Reconstructed model technique is successfully applied to measure short fatigue crack length in the testing work. According to elastic-plastic fracture mechanics method, it is put forward an estimated formula for short fatigue crack propagation rate at notch. Using ep (effective plastic strain range of crack tip) as a controlling parameter, the solution to the normalizing problem of propagation rate of short fatigue crack as well as long fatigue crack at notch for 45# steel are given.