Abstract:

Exper imental and analytical studies of effect of specimen thickness on fat igue cr ackgr owth behavior wer e car r ied out in domestic 2024-T 351 aluminum alloy. Fatigue cr ack growthtests wer e per formed under single- over loading conditions. The r esults showed that specimenthickness has significant effect on crack growth reta rdation, and over load shutoff r atio is not amater ial constant, which is also r ela ted t o the str ess stat e, loading and specimen thickness.Thick specimen has a lar ger overload shutoff r atio, and t he over load shutoff r atios cor respondingt o specimen t hickness should be used to predict t he fat igue cr ack growth life by J. B. Changmodel.

Key words: aluminumalloy, specimen thickness, fatigue crack growth, single-overloading