Analysis of a model for void growth and coalescence ahead of a moving crack tip

One mechanism for the slow, steady motion of a crack tip in plane strain is void growth and coalescence. A model of this process is formulated by isolating a geometrical cell containing a single void and extending the cell in uniaxial strain. A rigid-plastic material is assumed and the velocity field is analysed by means of a finite element procedure. From the results of the analysis, the dissipation of energy in the creation of crack surfaces is estimated as a function of the original void-size and the volume fraction of voids. Further, the shallow shape of dimples found experimentally is verified by the results of the analysis. A check on the accuracy is obtained by application of the numerical method to cases where analytical solutions are known.