The J Integral Approach in Elastic-Plastic Fatigue Crack Propagation

Linear elastic fracture mechanics (LEFM) is a consequence of the analytical description of the elastic stress distribution surrounding a crack tip [1] which is independent of geometry and applied load. As a consequence of LEFM the stress intensity can be uniquely described in terms of component geometry and applied load via the well known stress intensity factor, KI [2]. The resistance of a material to fracture is commonly described in terms of the experimentally determined fracture toughness KIC [3,4] and when used in conjunction with analytically determined component stress intensity factors, engineering judgements can be made regarding the possibility of eminent failure.