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Experimental study on dynamic response and energy-absorbing property of medium-fine grained granite under actual temperature |
SHI Heng,WANG Zhiliang,LI Hongru |
(School of Civil Engineering,Hefei University of Technology,Hefei,Anhui 230009,China) |
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Abstract The dynamic response and energy-absorbing property of medium-fine grained granite under the actual temperature were studied using the modified split Hopkinson pressure bar(SHPB). The complete stress-strain curve of the granite displayed three notable stages of elastic,plastic and strain-softening in the range of 20 ℃–500 ℃. When the temperature rose to 700 ℃,the plastic yielding platform in the curve appears. A rise in the strain rate caused the increase of the compressive strength of granite,but the effect of the strain rate decreased gradually as the temperature increases. Neither the temperature nor the strain rate showed the influence patterns on the elastic modulus. The increase of strain rate raised the energy-absorbing capacity of per unit volume(Ev),but the effects of strain rate on the value of Ev were quite diverse under the different temperatures. When the temperature was less than or equal to 500 ℃,the effects of strain-rate on the peak strain are relatively close,whereas the strain-rate sensitivity coefficient of the peak strain increased significantly at 700 ℃. Under the same loading pressure,the strain-rate ranges of the specimens treated under different temperatures differed widely,and the influence coefficients of the pressure were also distinct. The failure mode of specimen under the increasing strain rate at 500 ℃ and below changed from the axial splitting to fracturing. At the temperature of 700 ℃,all the specimens were pulverized.
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[1] |
李夕兵. 岩石动力学基础与应用[M]. 北京:科学出版社,2014:250-257.(LI Xibing. Rock dynamics fundamentals and applications[M]. Beijing:Science Press,2014:250-257.(in Chinese))
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