Fatigue Crack Growth Retardation after Single Overload Cycle in High Strengh Aluminium Weldments

고강도 알루미늄 합금 용접부에 있어서의 피로균열전파에 미치는 과하중 효과

Retardation or delay in fatigue crack growth due to overloads are important for the accurate prediction of fatigue lives of structural materials. In this study, retardation of fatigue crack growth in Al 6061-T6 weldments and heat affected zones (HAZ) after single overload cycle had been investigated. Retardation in both weldments and HAZ was observed. It was concluded that retardation in both weldment and HAZ was greater than in base metal due to microstructural change and crack branching and crack closure were major governing factor in retardation.