Some Micromechanical Aspects of Damage and Fracture

Abstract

The failure mode is described by means of elasto-plastic fracture mechanics and the main aspects of fatigue crack behaviour are itemized. The crux of the matter is the presentation of the pplicability limits of the three substantially different fatigue fracture mechanics equations based on fatigue crack propagation development. In the course of this, the microstructural effects,  predominantly crystallographic identification, grain dimension, and second phase structures are considered. For some sorts of FCC polycrystalline metals, the fatigue life and micro-damage heterogeneity are investigated, especially the stage of early plastic fatigue damage initiation while emphasizing slip theory and the localization homogenization technique. An internal damage variable d^s is applied to illustrate of the micro-damage of each slip system.