INITIATION OF PLASTIC LOCALIZATION IN POWDER-BASED MATERIALS

Experiments show that plastic localization bands may occur in material s during metal-forming processes. As plastic strains during metal-form ing processes are much larger than the elastic ones, the rigid-plastic model is assumed. Coupled temperature and damage effects are taken in to account. The necessary conditions for initiation of shear and delat ation localization bands under plain nonhomogeneous plastic flow are o btained from the conditions for bifurcation of the rates of the proces s parameters. Numerical examples show the initiation of localization b ands during metal-forming processes. (C) Elsevier, Paris.