The mechanism of ductile fracture is discussed by means of an analysis of energy balance at fracture of an ideally elastic-plastic solid containing a pressurized penny-shaped crack. According to the present model, the solid should satisfy an additional requirement that the yielded zone be localized in a narrow layer preceding the crack tip. The critical load determined by a maximum on the potential energy curve, is compared with that which follows from the ultimate plastic strain criterion for fracture. The results are also compared with the predictions of the theory of elasticity (Griffith, Sneddon, Sack). It is pointed out that the loading scheme has an important influence on the way in which fracture occurs. The equations obtained may be helpful in the studies of surface wear of hydrodynamically lubricated surfaces, weakened by flaws or cracks. Cracking in this case is attached to the notch brittleness effect, which is shown to be considerable for a pressurized crack.

This content is only available via PDF.
You do not currently have access to this content.