Effect of holes on in-plane shear(Mode Ⅱ)crack sub-critical propagation of rock

【作者】 谢海峰； 饶秋华； 谢强； 黎纵宇； 王志；

【Author】 XIE Hai-feng RAO Qiu-hua XIE Qiang LI Zong-yu WANG Zhi (School of Civil Engineering and Architecture,Central South University,Changsha 410083,China)

【机构】 School of Civil Engineering and Architecture,Central South University；

【摘要】 <正>Shear-box（i.e.compression-shear）test and newly designed electrically conductive adhesive method were used to measure shear crack sub-critical propagation time and rate of sandstone specimen.Different cubic specimens with and without holes were tested to study the effect of holes on the shear crack sub-critical propagation.Numerical and experimental results show that three independent variables of hole,the interval distance S,the distance between the center of hole and the crack tip L,and hole radius R, have different contribution to the ratio of stress intensity factor of the specimen with holes to that of the specimen without hole, K_Ⅱ/K_Ⅱ0.Increasing S and decreasing L and R will result in the decrease of K_Ⅱ/K_Ⅱ0and help crack arrest.The weight relation of the independent variables for K_Ⅱ/K_Ⅱ0is S>L>R.The specimen DH3 with the largest value of S and the smallest values of L and R has the longest sub-critical crack propagation time and the smallest sub-critical crack propagation rate.Adding two suitable holes symmetrically to the original crack plane in rock specimen is considered to be a potential method for crack arrest of rock.更多还原

【Abstract】 Shear-box（i.e.compression-shear）test and newly designed electrically conductive adhesive method were used to measure shear crack sub-critical propagation time and rate of sandstone specimen.Different cubic specimens with and without holes were tested to study the effect of holes on the shear crack sub-critical propagation.Numerical and experimental results show that three independent variables of hole,the interval distance S,the distance between the center of hole and the crack tip L,and hole radius R, have different contribution to the ratio of stress intensity factor of the specimen with holes to that of the specimen without hole, K_Ⅱ/K_Ⅱ0.Increasing S and decreasing L and R will result in the decrease of K_Ⅱ/K_Ⅱ0and help crack arrest.The weight relation of the independent variables for K_Ⅱ/K_Ⅱ0is S>L>R.The specimen DH3 with the largest value of S and the smallest values of L and R has the longest sub-critical crack propagation time and the smallest sub-critical crack propagation rate.Adding two suitable holes symmetrically to the original crack plane in rock specimen is considered to be a potential method for crack arrest of rock.更多还原