Cyclic inelasticity and high-cycle fatigue of metals with consideration of the stress gradient effect*

Abstract

Cyclic deformation behavior of metals and alloys under high-cycle loading in the nonuniform stress state is considered. A significant effect of the stress gradient on the cyclic inelastic deformation of the metal surface layers is shown. A model explaining the difference between the fatigue limits in the uniform and nonuniform stress states is proposed, which is based on accounting for the distinctions between cyclic stress–strain diagrams in the uniform and nonuniform stress states and for the fact that the fatigue limit is equal to the cyclic elasticity limit found for inelastic deformation typical of this class of materials.