Examination of the block shear fracture test method to measure the Mode-II critical stress intensity factor

Block shear fracture tests were conducted using specimens of western hemlock to determine the properties of the fracture mechanics under the Mode-II condition. In the test, a fixture standardised as the block shear test of solid wood in the Japanese Industrial Association (JIS Z2101-2009) was used. The specimen configuration, location of the crack, and initial crack length were varied, and the effects of these conditions were examined. The Mode-II critical stress intensity factor was effectively obtained when the initial crack was introduced at the opposite location to that where the shear load was applied using a specimen with a cubic configuration. Additionally, the introduction of the additional crack length due to the fracture process zone ahead of the crack tip was also effective in the block shear fracture test and other Mode-II fracture tests.