Mode Ⅱ fracture mechanism of direct shearing specimen with guiding grooves of rock

来源期刊：中国有色金属学报(英文版)2001年第4期

论文作者：饶秋华 孙宗颀 王桂尧 徐纪成 张静宜

文章页码：613 - 616

Key words：Mode Ⅱ fracture; fracture mechanism; rock; direct shearing test; guiding groove

Abstract: Fracture mechanism of direct shear specimen with guiding grooves of rock was investigated experimentally and numerically in order to explore a favorable stress condition for creating Mode Ⅱ fracture and guide design of specimen configuration for determining Mode Ⅱ fracture toughness of rock,K_ⅡC . The experimental and numerical results demonstrate that Mode Ⅱ fracture can be successfully achieved in the direct shearing specimen with guiding groove because the guiding grooves added , in the notch plane can generate a favorable stress condition for Mode Ⅱ fracture, i.e. tensile stress at the notch tip is completely depressed and shear stress at the notch tip is very high in the notch plane. The optimum design of the specimen configuration for K_ⅡC testing should aim to reduce tensile stress to be compressive stress or be lower than tensile strength and greatly increase shear stress at crack tip.