中國有色金屬學(xué)報(英文版)
Transactions of Nonferrous Metals Society of China
| Vol. 11 No. 4 August 2001 |
with guiding grooves of rock
WANG Gui-yao(王桂堯)2, XU Ji-cheng(徐紀(jì)成)3, ZHANG Jing-yi(張靜宜)3
（1. College of Resources, Environment and Civil Engineering,
Central South University, Changsha 410083, P.R.China;
2. Department of River and Sea, Changsha Communications University,
Changsha 410076, P.R.China;
3. Open Lab of Mechanics, Central South University,
Changsha 410083, P.R.China）
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,KⅡC . 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 KⅡC 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.
Key words: Mode Ⅱ fracture; fracture mechanism; rock; direct shearing test; guiding groove
