A numerical study of ductile void growth under dynamic loading conditions

Abstract

A numerical study of void growth at differing global strain rates in the range 149s -~ -2240s -1 and at start temperatures between 173K and 573K has been carded out for a material containing a threedimensional periodic array of equally spaced, initially spherical voids. To take account of the effect of strain rate and temperature on the flow stress under dynamic adiabatic conditions, the well-established Zerilli-Armstrong constitutive relations for pure copper and iron have been employed. An instability criterion based on the maximum mean tensile stress has been used to identify the point at which unstable void growth occurs. For both materials, the strain at instability has been found to be dependent on stress triaxiality and start temperature but only weakly affected by strain-rate.