节点文献
Experimental study on time-dependent stress and strain of in-plane shear(Mode Ⅱ)fracture process of rock
【Author】 WANG Zhi RAO Qiu-hua XIE Hai-feng (School of Civil and Architectural Engineering,Central South University,Changsha 410075,China)
【机构】 School of Civil and Architectural Engineering,Central South University；
【摘要】 <正>Shear-box test with strain measurement was used to study time-dependent stress and strain of in-plane shear（Mode Ⅱ） fracture process of rock and to reveal the mechanism of Mode Ⅱ fracture.Numerical results show that the maximum shear stress τmaxat the crack tip is much larger than the maximum tensile stress σ1 and the ratio of τmax/σ1 is about 5,which favors Mode Ⅱ fracture of rock.Test results indicate that the strain—time curve comprises three stages:the linear deformation stage,the micro-cracking stage and the macroscopic crack propagation.The strain in the direction of the original notch plane is negative,due to restraining effect of compressive loading applied to the original notch plane.Both σ1.and τmaxare increased as the load increases,but the slope of τmaxis larger than that of σ1 and the value of τmaxis always larger than that of σ1.Therefore,τmaxreaches its limited value at peak load before σ1 and results in Mode Ⅱ fracture of rock.Shear-box（i.e.compression-shear）test becomes a potential standard method for achieving the true Mode Ⅱ fracture and determining Mode Ⅱ fracture toughness of rock.
【Abstract】 Shear-box test with strain measurement was used to study time-dependent stress and strain of in-plane shear（Mode Ⅱ） fracture process of rock and to reveal the mechanism of Mode Ⅱ fracture.Numerical results show that the maximum shear stress τmaxat the crack tip is much larger than the maximum tensile stress σ1 and the ratio of τmax/σ1 is about 5,which favors Mode Ⅱ fracture of rock.Test results indicate that the strain—time curve comprises three stages:the linear deformation stage,the micro-cracking stage and the macroscopic crack propagation.The strain in the direction of the original notch plane is negative,due to restraining effect of compressive loading applied to the original notch plane.Both σ1.and τmaxare increased as the load increases,but the slope of τmaxis larger than that of σ1 and the value of τmaxis always larger than that of σ1.Therefore,τmaxreaches its limited value at peak load before σ1 and results in Mode Ⅱ fracture of rock.Shear-box（i.e.compression-shear）test becomes a potential standard method for achieving the true Mode Ⅱ fracture and determining Mode Ⅱ fracture toughness of rock.
- 【会议录名称】 Proceedings of the 9th National Conference on Rheology
- 【会议名称】The 9th National Conference on Rheology
- 【会议时间】2008-09
- 【会议地点】中国湖南长沙
- 【分类号】TU452
- 【主办单位】Chinese Society of Rheology(CSR)、Central South University of Forestry & Technology(CSUFT)、Xiangtan University(XTU)、Hunan University of Technology(HNUT)