Abstract: Impact tests are conducted on magnetite quartzite samples by using SHPB apparatus with different impacting velocities.Based on the test results,the law of energy dissipation and fragment-size distribution of rocky materials under impacting loads was analyzed,and then the relation models of the fragmentation energy consumption of magnetite quartzite were setup.The concepts of strain rate intensity index and energy-time density were suggested.The concepts reveal that the effective energy consumption is not only associated with the totally input energy,but also is closely related to the energy-time density.By analyzing the samples fragmentation and compared with sustains time and strength of reflect stress waves,the relationship models of dynamic strength of rock related to strain rate and energy-time density were established initially.From this,the notion of energy output structure was described quantitatively,and the bridge of explosives energy output to energy consumption of rock fragment was set up,and a new idea of energy coupling between rocks and explosives was proposed as well.

Key words: Strain rate, Impact breaking, Effective energy consumption, Energy density per unit time