A MODELING STUDY OF THE EFFECT OF STRESS STATE ON VOID LINKING DURINGDUCTILE FRACTURE

The deformation and fracture behavior of sheer specimens containing ei ther pairs of ''pseudo''-random arrays of equi-sized holes has been ex amined in both uniaxial and equal-biaxial tension utilizing experiment as well as computer simulation. Our results show for this plane-stres s situation that hole linking is always caused by flow localization wi thin the ligaments between neighboring holes. The imposed strains to i nitiate flow localization and subsequent ligament failure are sensitiv e to stress state (uniaxial versus biaxial) and the location of the ne ighboring hole(s). A significant observation is the influence of stres s state on the multidirectionality of hole linking paths: specifically , increasing the biaxial component of the stress state increases the n umber of holes that can participate in a hole-linking process. A relat ed implication is that the strain range over which void linking occurs decreases with increasing triaxiality of the stress state; in effect, after the initiation of void linking, its propagation is accelerated under biaxial or triaxial tension.