RESEARCH ON DYNAMIC MECHANICAL PROPERTIES, CONSTITUTIVE MODELS AND STATE EQUATIONS OF GRANITE

The purpose of this study is to investigate the dynamic mechanical properties, constitutive models and state equations of granite under strong dynamic loading conditions. To this end, split Hopkinson pressure bar (SHPB) and light gas gun (LGG) systems were used to conduct pressure rod tests and flyer plate impact tests to obtain the dynamic mechanical parameters of granite under different conditions. The results of the pressure rod tests show that granite exhibits a significant strain rate effect in the range of 80~320 s^–1, with its strength and strain rate approximately following an exponential relationship. The impact tests show that the velocity of the impacting particles has a significant effect on the propagation velocity of the shock wave, with the compressibility of the specimen gradually increasing with increasing loading velocity and then decreasing again. Finally, based on the experimental data, the HJC (Holmquist–Johnson–Cook) constitutive model, Gruneisen state equation, and dynamic yield strength parameters of granite under strong dynamic loading conditions were given.