Contact fracture of brittle materials: A comparison of 2-D and 3-D fracture mechanics solutions

The results of calculations of the mode I stress intensity factors associated with surface-breaking semi-elliptical cracks situated close to Hertzian contacts are presented. The ellipticity of the crack is shown to have a pronounced effect on the magnitudes of calculated surface and crack-bottom K I values; the implications of this for determining the fracture toughness of brittle materials via Hertzian indentation are discussed, as is the stability of the ensuing fracture.