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 τmax at 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 τmax are increased as the load increases, but the slope of τmax is larger than that of σ1 and the value of τmax is always larger than that of σ1. Therefore, τmax reaches 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.
Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
