Abstract:In order to study the kinetic characteristics of coal under impact damage, the impact damage test under different strain rates is carried out on coal samples with the 50 mm diameter split Hopkinson pressure bar test system. The results show that the fragmentation process can be divided into four stages, namely the compaction stage, the linear elastic stage, the crack propagation stage and the damage stage. Under different strain rates, the strain of the coal sample increases with time. The larger the strain rate, the greater the strain-time curve slope of the coal sample; The dynamic deformation modulus and dynamic compressive strength of the coal increase with the increase of strain rate, and fluctuate within a certain range; There is a clear correlation between the coal sample impact crushing block distribution and the strain rate.
