EVOLVING FRACTURE PROCESS ZONEWITH DISLOCATION MOTION AS PRECURSOR OF CRACKS

摘要

In this paper the dynamics of an evolving fracture process zone with dislocation motion is investigated.The considerations arebased on a nonlocal theory of elastoplasticity characterized by balance of standard forces and nonlocal balance of materialforces acting on dislocations.It is shown that the configurational stresses and the configurational internal and external bodyforces acting on an evolving process region can be derived as functions of standard and material forces and stresses,respectively.Introducing thermodynamically admissible constitutive equations, satisfying the second law of thermodynamics,generalized Eshelby tensor and configurational internal body forces can be split into two parts, a non-dissipative equilibriumpart, derivable from the free energy, and a dissipative non-equilibrium part, which under certain symmetry conditions can beobtained from a dissipation pseudo-potential.The dissipative parts can be considered as driving parts.They govern theevolution of the fracture process region.