Abstract
It is widely recognized that stress intensity factor around crack tip is quite usefuto explain quantitatively material damage accompanying cracks and researching works are ongoing in this area in various ways. Generally, a crack can be regarded as a notch in the extremity with a sharp tip of infinitively small radius and it is considered important to comfirm experimentally the relation between crack and notch and the effect of crack tip shapes on stress intensity factors. In this paper. stress intensity factors were determined by hybrid methods of photoelastics and caustic methods. The model specimen was made from epoxy resin plate with four crack tip shapes (radius, slot, cast, razor). The effect of crack tip shapes on stress intensity factors was experimentally compared together with factor of rupture and stress concentration factor, and the results were discussed.
