アルミニウム合金切欠き材の疲労強度に及ぼす加工傷の影響

抄録

The purpose of this study is to investigate effect of machine processing scratches on fatigue strength of a notched specimen of aluminum alloy. In this study, strain-controlled fatigue tests were carried out for two types of notched specimens with machine processing scratches. The fatigue strengths of notched specimens decreased by more than the elastic stress concentration factor due to the notch. To discuss the fatigue strength reduction, the specimen and fracture surfaces were observed carefully. The observations showed that the fatigue cracks initiated from the machine processing scratches and they are aligned around the notch root due to the stress concentration. As a result, the fatigue strength reduction factor became greater than elastic stress concentration factor.