Surface Flaws In Glass And The Statistics Of Flaw Distribution

The intrinsic and practical strengths of glass may be regarded as statistical properties government by distribution functions and obeying extreme values statistics. The distribution giving the average number of failure points per sample as a function of stress is found from the experimental distribution of breaking stresses when a sufficiently large number of identical samples are tested. For failures originating from two sources, a procedure is proposed for evaluating the two-sample distribution functions separately from the experimental results. The results expected from bending tests on rods and bars are calculated for surface flaw distributions in which the density of flaws increases as a power of the stress.