Abstract
Silicon carbide plate specimens containing a through-thickness crack, on which stress intensity can be calculated using two-dimensional stress analysis, were prepared by a new method developed in the present study, and fracture toughness tests were performed on these specimen. The specimen geometry was quite similar to that of the ASTM Standards compact tension specimen. A compressive load was applied to the upper and lower surfaces of a specimen containing a narrow slit as a crack-starter. This produced a tensile stress near the slit end and a compressive stress far from it. The loading point was changed moment at the notch root. The obtained fracture toughness value from the specimen is almost independent of the crack length between 0.5 and 0.7 in the ratio to the specimen width. It is also independent of specimen thickness in the experimental range of 3.0 and 9.5 mm.
