Specimen size requirements for determining the inherent fracture toughness of rocks according to the ISRM suggested methods

Influence of thermal treatment on mode I fracture toughness of certain Indian rocks

“…The fracture toughness of a given rock can be evaluated under any definite type and magnitude of loading because it can be explained in terms of the Stress Intensity Factor (Ayatollahi, 2015). To date, four different methods have been suggested by the International Society for Rock Mechanics (ISRM, 2007) for the measurement of fracture toughness, namely the short rod specimen method (SR) (Matsuki et al, 1991;Ouchterlony, 1988), the chevron bend specimen method (CB) (Ouchterlony, 1990), the crack chevron notched Brazilian disc (CCNBD) specimen methods (Fowell, 1995) and the crack straight through semi-circular bend (CSTSCB) specimen method .…”

Assessment of fracture toughness in ornamental stones

“…Concerning the engineering uses of stone (including those that implicate the study of the cutting processes) it is also important to observe whether the trend of the data given by the different testing geometries (implicating different test methodologies) is consistent [28]. Parallelepiped specimens are easier to be used when studying ornamental stones, which are available in the form of slabs and plates.…”

Fracture toughness of ice and firn determined from the modified ring test

“…In rocks, ceramics, concrete and metals, specimen-size requirements are designed to insure either plane-strain testing conditions, a critical amount of stable-crack extension prior to unstable-crack growth (Matsuki. 1991) or a minimum extent of inelastic crack-tip deformation (e.g.…”