Abstract: Variable cross-section split Hopkinson pressure bar (SHPB) with a diameter of 50 mm is adopted to implement radial loading to the mine sandstone Brazilian disc, which has a thickness-diameter ratio of 0.5. Dynamic tensile tests at various loading rates are obtained by altering impact loading pressures. Through investigating energy composition and dissipation characteristics of sandstone specimens during the dynamic tensile failure process, this paper tries to analyze the failure forms, average strain rate effect and dynamic tensile strength from energy dissipation perspective. It is found that energy absorbed by specimen mostly dissipates in the damage evolution and deformation failure process, which corresponds well to the tensile performance of sandstone under dynamic loads. The results showed that tensile strength and absorbed energy increase logarithmically with the average strain rate, a remarkable strain rate correlation. The results can provide some reference for dynamic tensile performance research of rocklike brittle materials.

Key words: rock mechanics, Brazilian disc, split Hopkinson pressure bar(SHPB), energy dissipation, strain rate effect