General statistical description of the fracture particulates formed by mechanical impacts of brittle materials

The solid particulates formed in standard diametral and axial impact tests of small cylindrical specimens of glasses and ceramics were found to have size distributions that plotted as straight lines on log-normal graphical coordinates. Generalized log-normal parameters were defined for these empirical particle-size distributions according to particle masses (or volumes), surface areas, and particle numbers, including geometric mean shape factors for these distributions. These descriptive parameters were found to correlate with impact severity measured as impact kinetic energy per unit volume of the specimen for representative brittle materials, both vitreous and crystalline. These correlations also define impact strength as a property of materials and can be further generalized to model the impact-fracture process for large-scale as well as small-scale impact effects. Applications of the log-normal analysis were made for the characterization of particles adhering to dry surfaces and for the conditions under which particle fusion may occur in mechanical impacts.