Abstract
In this paper we conducted shear-type tests with initial cracks on block-shear-specimen or not.
For block-shear-specimens without initial crack, the longer the shear length is, the smaller the shear strength. It is difficult to evaluate the real shear strength based on JIS methods. For some type specimens with initial cracks, we defined maximum load as crack starting criteria and calculated energy release rate in theory.
As a result, type 3 specimen named in this paper is useful for evaluate mode 2 fracture toughness.