Quantitative and Qualitative Comparative Study on Fatigue Life Prediction of Aluminium Alloy under Overloads (Underload) Effects

摘要

The present paper focuses on the study of the overload / underload effects on fatigue life prediction. Different configurations of loading conditions are used to investigate the various types of interactions. The retardation effect due to different scenarios of applied overload - underload and frequency are studied for a 7075-T73 aluminum alloy. The retardation effects are quite well explained by means of computational analysis using AFGROW fatigue life predictions code. A comparative study is then undertaken in order to quantify the retardation effect and to establish correlation with fatigue life prediction under constant amplitude loading. The results obtained allow quantitatively and qualitatively to explain the effects of overloads sequence, intervals and frequencies on the retardation phenomena which can not be neglected in fatigue life prediction. The results put into evidence the high sensitivity effect of the ratio of overload to nominal stress on the retardation phenomena. The results of the present investigation agree quite well with those found in literature.