Experimental Study On Dynamic Tensile Failure Of Several Rocks

It’s an important significance of mastering the mechanic properties to mining, atpresent, the mechanical properties of the static loads has achieved fruitful results.However, with the wide application of Engineering Blasting in mining, staticmechanical properties of rock has been unable to meet the needs of projects. It’snecessary to investigate and grasp the dynamic mechanical properties for betterserving of mine blasting. The rock dynamic is more complex than rock static. So theresearch of the dynamic tensile mechanical properties of the rock is the basis ofoptimizing blasting. Several typical rock samples are analyzed by the usage ofdiameter of50mm split Hopkinson pressure bar (SHPB), to provide theoreticalguidance and technical support for blasting design, which also explores an effectiveexperimental method for the further research of the energy matching betweenexplosive and rock.It mainly works around the following3aspects:Firstly, using the SHPB which is improved byT2Red copper pulse shaper tomake radial impact on rock specimens of granite, magnetite and phyllite underdifferent speed; and also processing2parallel planes as loading surface on thespecimens to turn the specimens into Flattened Brazilian Disc (FBD) specimens. Byusing the Matlab software to process the experimental date, it shows the stress straincurve, strain rate, elastic modulus and tensile strength of3rock specimens which canbe used for comparing with the static test. The mechanics characteristics analysis of3specimens under the same loading speed or the same rock under different loadingspeed are also presented at the same time.Secondly, though the radial impact on FBD and BD granite, the2specimens canbe analyzed contrastively in the way of the failure time, strain rate, failure mode andthe inhomogeneity of time.Finally, building the relationship of the energy input, output and effectivefragmentation energy consumption, and trying to analyze the dynamic tensile strengthof the rock from the perspective energy.In this paper, the research work is based on administered front, the conclusionprovides effective support for implementation of rock blasting mining optimization,also opened up a new research approach for the research of blasting optimization.