Microstructural and geometrical size effects on the fatigue of metallic materials

It has been widely recognized that the fatigue performance of metallic materials is significantly affected by both geometrical and microstructural sizes. Based on a literature review of the recent development of the size effects (SEs) on fatigue, this paper presents a panorama of the correlation of SEs with low-cycle fatigue, low-cycle dwell fatigue, high-cycle fatigue and very-high-cycle fatigue, respectively. The experimental and numerical methods to investigate SEs and their advances and limitations are critically presented. Finally, the research gap, key challenges and prospects ahead are discussed.