ABSTRACT
ABSTRACT: A complete stress-strain curve provides thorough information of rock deformation. The method for determining the static version of complete stress-strain curve of intact rock has been suggested in 1999, but its dynamic counterpart has not been brought up yet. The main reason lies in the complicated characteristics of dynamic loading, material response and the rate dependent properties of rock materials. The SHPB (Split Hopkinson Pressure Bar) device, with merits of accuracy and easy operation, can obtain stress-strain information of materials at high strain rates. But when it was used for tests of rocks, new problems such as stress non-equilibrium, pre-mature failure come up. At the same time, as rock materials are rate dependent, it becomes very important to get constant strain rate of specimens in tests. In this paper, the shortcomings of traditional SHPB for rock tests were listed and the improvements were introduced briefly. Then the two most important factors in SHPB test, strain rate and stress equilibrium, were discussed based on test results. Finally, some basic ideas of test system and data processing were suggested.
