MIXED-MODE FRACTURE IN BIAXIAL STRESS STATE - APPLICATION OF THE DIAMETRAL-COMPRESSION (BRAZILIAN DISK) TEST

Mixed-mode fracture of soda-lime glass was studied using a diametral-compression test that features disk specimens with symmetric through-cracks. The test enables one to study fracture under pure mode I loading, pure mode II loading, or any combination of mode I and mode II loading by a simple alignment of the crack relative to the diameter of compression loading. The disk specimens were precracked with the aid of both chevron notches and water-assisted subcritical crack growth. The directions of noncoplanar crack extensions and the relative magnitudes of mode I and mode II stress-intensity factors for mixed-mode fracture under inert conditions were compared to the predictions of three different mixed-mode fracture theories.