Nonlocal plastic models for cohesive-frictional materials

摘要

Two classes of nonlocal models for softening materials with nonassociated plastic flow are described and their localization properties are analyzed. Models of the first class are based on standard plasticity and use a hardening-softening law dependent on both local and nonlocal cumulative plastic strain. Models of the second class are based on combination of plasticity and damage mechanics and use a damage evolution law dependent again on local and nonlocal cumulative plastic strain. Conditions for continuous and discontinuous bifurcations from a uniform state in an infinite medium are derived, and the evolution of localized plastic zone is illustrated by simple one- and two-dimensional examples.