Abstract:
To compare the dynamic mechanical properties and destruction forms of sandstone and granite with the strain rate ranging from 49s
-1to 97s
-1, impact compression tests were conducted using the split Hopkinson pressure bar(SHPB) test device with a diameter of 100mm. The results show that the dynamic compressive strength of the two materials, the extent of damage and energy absorption increased with the increase of strain rate, but the energy dissipation rate of granite gradually decreased with the increase of strain rate, and all of them show strain rate correlation; the initial elastic modulus, peak strain and energy dissipation rate of sandstone under three types strain rates show little difference and a weak strain rate sensitivity.By analyzing the energy absorption and dissipation rate curves in the loading process, the dynamic failure modes were analyzed from the perspective of microstructure. Through the verification of the test validity, it is proved that the test meets the assumption of uniformity better.