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Abstract It has been found recently that the dynamic compressive strength of rock-like materials testing on split Hopkinson pressure bar(SHPB) is increased with the increase of testing strain-rate. The dynamic compressive strength increasing is attributed to the combined action of material strain-rate effect，lateral inertial effect and end friction effect，and in actual SHPB tests they are coupled together and could not be separated from each other. To determine the material strain-rate effect of the rock-like materials in SHPB tests，it needed to remove the dynamic compressive strength increment caused respectively by lateral inertial effect and end friction effect. In this study，the numerical simulation method is employed to simulate the SHPB tests for rock-like materials. The effect of material strain-rate，lateral inertia and end friction is assumed to be uncoupled. In numerical SHPB tests，when the effect of material strain-rate and lateral inertia is not considered，the predicted dynamic compressive strength increment of rock-like materials induced only by the lateral inertia effect is obtained. Similarly，when the effect of material strain-rate and end friction is not considered，the dynamic compressive strength increment of rock-like materials obtained from numerical SHPB tests caused only by the end friction effect is determined. Then removing the dynamic compressive strength increment caused respectively by the lateral inertial effect and end friction effect from the dynamic compressive strength data obtained from actual SHPB tests，the material strain-rate effect of the rock-like materials in SHPB tests is determined. Finally，the assumption proposed in this study is verified by comparing the results with other research.
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Received: 26 November 2012
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2013, Vol. 32 
