抄録
Recently the authors have derived various new types of path independent integrals in which the theoretical limitations of the so-called J integral are overcome. First, for elastodynamic crack problems, a path independent integral J' which has the physical meaning of energy release rate was derived. Later more general forms of path independent integrals T and T were derived, which are valid for any constitutive relations under quasi-static as well as dynamic conditions. This paper presents the theoretical and computational aspects of these integrals, of relevance in nonlinear dynamic fracture mechanics. Finite element analyses were carried out for an example problem of a center-cracked plate subject to a uniaxial impact loading. The material behavior was modeled by three different constitutive relations such as linear-elastic, elastic-plastic, and elastic-viscoplastic cases. The applicalility of the T integral to nonlinear dynamic fracture mechanics was shown with the numerical results.
