Tensile Strength of Laurentian Granite under Static and Dynamic loadings
Due to difficulties associated with sample gripping in direct tension, indirect methods are commonly used to quantify the tensile strength of rocks. In this work, an indirect tensile test method - semi-circular bend (SCB) is used to investigate the tensile (flexural) strength of Laurentian granite (LG). The static tests are conducted with a servo-controlled material testing machine and the dynamic experiments are carried out using a split Hopkinson pressure bar (SHPB) system. For dynamic tests, pulse shaping technique is adopted to achieve dynamic force balance on both ends of the sample. The dynamic force balance eliminates loading inertial effect in the sample and thus enables quasi-static stress analysis. Momentum-trap technique is also employed in SHPB to ensure single-pulse loading. Finite element method is used to relate the failure load to the strength of the sample. Rate dependence of the strength is observed. The value of the flexural strength is higher than the tensile strength measured using Brazilian disc method. We rationalize this difference using the non-local failure theory. Furthermore, a coupled Discrete element - Finite element method (Fem/Dem) in conjunction with the smeared crack model is utilized to simulate the fracture process of a dynamic SCB test. The fracture pattern obtained from the simulation agrees with that of the recovered sample.
Semi-Circular Bend (SCB) Laurentian granite flexural strength SHPB Fem/Dem
F.Dai K.Xia
Department of Civil Engineering and Lassonde Institute, University of Toronto Toronto, Ontario, Canada M5S 1A4
国际会议
香港
英文
1-5
2009-05-19（万方平台首次上网日期，不代表论文的发表时间）