The values of mode II fracture toughness reported in the literature for several rocks are
studied theoretically by using a modified criterion based on strain energy density averaged …

The centrally cracked Brazilian disk specimen subjected to diametral compression has been
widely used to study mode I, mode II and mixed mode I–II fracture behavior of rocks. The …

The influence of specimen size on the measured values of true mode II fracture toughness
(K IIc) of rocks have been investigated both experimentally and theoretically. In the …

Fracture toughness, as a measure of resistance against crack instability and propagation, is
one of the most important parameters in fracture mechanics of rocks and other solid …

A new method, compression-shear test, has been developed for determining the mode 11
fracture toughness KIIC of rock. The effect of the specimen thickness B, the dimensionless …

A series of tests with centrally cracked Brazilian disc and un-cracked Brazilian disc
specimens were conducted to investigate the relation between the mode II fracture …

A semi-disk specimen containing an angled edge crack has been used in the past for
conducting fracture tests on a brittle rock named Johnstone [Fracture testing of a soft rock …

This paper presents a proposed cracked Brazilian disk test procedure to determine the
envelopes of mixed mode I-II fracture toughness for brittle rocks. This test uses circular disks …

Up to now, several methods have been proposed to determine the mode I fracture
toughness of rocks. In this research, different cylindrical and disc shape samples, namely …

The critical mode I stress intensity factor obtained from fracture tests on laboratory
specimens is often used as fracture toughness in brittle and quasi-brittle materials. However …