Abstract
The diametral compression testing method, in which a simple penny shaped disk is loaded along a diameter until it splits, is convenient for determining the fracture strength of brittle materials. The maximum tensile stress at the center of disk σH is derived accurately by considering the Hertzian contact width as follows;
σH={1-1.15(b/R)2+0.22(b/R)3}σP; σP=P/πRt
where R, t and b are the radius, thickness and contact half width of the disk specimen, respectively. σP is the uniform tensile stress on the loading axis when the disk is compressed by the point force P. Furthermore, the correction in the diametral compressive strength for the effects of stress distribution and specimen volume is considered according to the Weibull's statistical theory, in order to apply this method to practical uses.
