Editorial

Design of mechanical components is mainly performed in the elastic domain; however, in order to initiate fatigue cracks, plasticity is needed on the either microscopic or macroscopic scale, depending on the fatigue regime (high cycle versus low cycle).From a macroscopic point of view, plasticity can be induced by the shape irregularity of the components or by overloading.Locally, plasticity is influenced by the microstructure of the material (porosity, inclusions, grain orientation. ..).Moreover, components often receive treatment, such as deep rolling, shot peening, and prestressing, which generate local plasticity resulting in a residual stress field that influences the fatigue strength.