Path Independent Integrals and Crack Growth Parameters in Nonlinear Fracture Mechanics

Abstract

In this paper some important aspects of nonlinear fracture mechanics are discussed; we will concentrate to fracture initiation and quasistatic crack growth of a macroscopic crack in an inelastic material, where plasticity or creep play a considerable role. From the engineering point of view these items mainly refer to ductile structural metals. Not considered are many other topics of modern nonlinear fracture mechanics like distributed microcracking, damage mechanics aspects, composite materials, fatigue or dynamic problems. Mainly the basic theoretical facts will be discussed, no attention is payd to specific problems of engineering application. In addition, this analysis in most cases is restricted to plane problems and monotonic unidirectional loading; the material is assumed to be isotropic and generally homogeneous.