裂纹扩展中的部分止裂现象及其对疲劳寿命的影响

PARTIAL ARREST PHENOMENA IN CRACK GROWTH AND ITS INFLUENCE ON FATIGUE LIFE

由实验发现超载比在1.4到2.2之间时,裂纹有一停止扩展阶段,因此把超载之后的迟滞区分为两部分,即部分止裂区和裂纹扩展恢复区。根据实验现象,提出了一个受超载比和超载数目影响的部分止裂次数经验公式,将此公式应用到 AFFDL 模型中进行疲劳寿命估算,计算结果与实验结果符合得很好。

Based on experiment,when the overload ratio was between 1.4 to 2.2,the partial arrest phenome- na was noticed in the retarded zone.So the retarded zone was divided into two parts:the pertial arrest period and the crack growth regained period.An empirical formula was offered about the partial arrest number which was dominated by the overload ratio and overload number.By Combining this formula with AFFDL model,fatigue crack growth life could be predicted.The prediction was in good according with the experiment data.