A mechanism of void growth in the region of the plastic zone ahead of a crack-tip

The mechanism of void growth in the region of the plastic zone ahead of a crack tip proposed earlier is further developed. As a result of partial annihilation of lattice dislocations representing the plastic zone with elastic dislocations representing the void, ledge steps are formed on the void surface causing void growth. A detailed dislocation model of the mechanism of void growth is illustrated using both the discrete dislocation analysis and the continuous distribution method. The latter is particularly developed to provide the scaling methods, so that the results can be readily obtained for different sizes of the crack and the void as well as for different positions of the void with respect to the crack. Application of these results to void growth in the region of the plastic zone ahead of a crack tip subjected to alternating stresses and creep is also suggested.