Design of mechanical components against fatigue is vitally important to prevent sudden and unexpected fatigue damage. Due to the complex nature of welded joints because of the changes in material properties due to heat and the geometry of weld beads, designing against fatigue becomes an even more challenging task Over the years, several methods that can accurately and effectively determine fatigue related parameters were developed. In this paper, a state of the art literature review of studies based on strain energy density (SED) approaches and their use in fatigue evaluations are presented. While a theoretical background is provided, the main focus of the paper is to highlight applications of SED approaches. In order to achieve this objective, papers with varied topics that related to SED are evaluated. C1 [Karakas, Ozler; Tuzun, Nail] Pamukkale Univ, Engn Fac, Dept Mech Engn, Denizli, Turkey.