Mechanisms for fragment formation in brittle solids.

A model for mode I fracture in brittle materials is used to elucidate the relationship between characteristics of the fracture process, such as crack roughness, fractal dimension, and fragment size distributions. It is shown that different roughness in local regions of the crack path leads to different mechanisms for the subsequent fracture of those regions. Formation of two robust power laws for the distribution of formed fragments is observed, governing the size distribution of smaller and larger fragments. We connect measurements in fragment size distribution with the local roughness of cracks in the region of fragment formation.