Abstract：The impact test and dynamic Brazilian test using the pendulum hammer driven SHPB apparatus were conducted to measure the viscosity coefficient of sandstone and artificial rock and to examine the loading rate effect. The viscosity coefficients of sandstone and artificial rock A and B are 100，10 and 5 kPa•s respectively and were determined with the combined method of experiment and numerical simulation. The dynamic tensile strength of the sandstone and artificial rock samples increase with the loading rate，showing the strong strain-rate dependency. The influence of viscosity on loading rate effect of dynamic tensile strength is validated，but they are not positive correlated. The energy of stress wave propagation in the sample attenuates with the sandstone viscosity under the low loading rate. So the crack initiates at the center of Brazilian sample and propagates along the loading diameter，but the sample is not separated into two halves. The position of crack initiation at the center of sample is thus validated.
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2017, Vol. 36 
