Abstract:
In order to study the dynamic mechanical properties of hard coal and rock in northern Shaanxi Province, the basic dynamic and static tests of coal and rock specimens were carried out by using stress loading system and split Hopkinson pressure bar (SHPB) test device, and the failure mechanism was studied. The results show that under static load, most of the coal and rock specimens are damaged by single crack, while under dynamic load, the failure forms are relatively rich, such as splitting failure at low strain rate and crushing failure at high strain rate. The correlation between elastic modulus and strain rate of peak stress is significant, but the correlation between peak strain rate is weak. Under dynamic loading mode, the closure time of defects such as voids, cracks and particle spacing is too short due to the fast loading speed, which shows that the stress-strain curve is missing on the macro level.