Distribution of Cracks on Glass Surfaces

The ball indentation experiment was used to determine the density distributions of surface cracks of various severities on flat glass plates. The fracture load histograms that result from a large number of indentations with a ball indenter are the basis of the information on the distribution of cracks. The integral equation relating the probabilities of fracture as a function of load to the crack distribution function was solved with an operational inversion by means of the two-sided Laplace transform. The distributions of cracks were calculated for a chemical Pyrex glass and for a window glass.