Abstract:In order to study the influence of strain rate on the dynamic split tensile properties of rock,the dynamic split tensile tests of flattened Brazilian disc specimens of amphibolite,sericite-quartz schist and sandstone,are carried out by using split Hopkinson pressure bar(SHPB) equipment with a diameter of 100 mm improved by copper waveform shaper. The changing rules of tensile sensitivity coefficient,radial strain,tensile Young?s modulus and failure modes are analyzed. Experimental results show that the tensile sensitivity coefficients of three rocks increase with the increase of strain rate,amphibolite is most sensitive to strain rate and sandstone is least sensitive to strain rate. The radial peak strain of three rocks is proportional to strain rate,and the radial ultimate strain of sandstone is the biggest. The Young?s moduli of three rocks in unloading process are greater than those in loading process. The failure modes of three rocks are closely related to impact velocity.
刘世奇,李海波,李俊如,等. 有侧向压力的岩石材料动态直接拉伸试验装置[J]. 岩土力学,2007,28(11):2 365-2 374.(LIU Shiqi,LI Haibo,LI Junru,et al. An equipment for dynamic direct tension tests of rock material under confining pressure[J]. Rock and Soil Mechanics,2007,28(11):2 365-2 374.(in Chinese))
[2]
HAO Y,HAO H,ZHANG X H. Numerical analysis of concrete material properties at high strain rate under direct tension[J]. International Journal of Impact Engineering,2012,39(2):51-62.
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