A Review on the Mechanisms and Analysis of Fatigue in Ductile Materials

In civil engineering, fatigue can be referred to as the loss in structural performance of engineering components when subjected to repeated cyclic loads. Fatigue is identified as one of the leading factors that determines the lifespan of an engineering structure. Fatigue develops in the form of small and localized cracks which gradually propagates subcritically until the engineering component is structurally incapable to satisfy the serviceability conditions and ultimately fails. Due to the engineering importance of the phenomenon, fatigue is studied extensively in order to obtain a better understanding of the phenomenon and its manifestation in different engineering components. Over the years a number of mechanisms and models have been developed in order to explain, analyze and predict the effects of the phenomenon on various components. The three key factors that have been identified to have influenced the fatigue life of engineering components include the material properties of the engineering component, the geometry of the engineering component and the load pattern to which the engineering component is subjected. This paper aims to give a brief and consolidated overview of the various mechanisms, the different models and the influence of the various factors on the fatigue performance of components composed of ductile materials.