Research on the average fragment size of rock dynamic fragmentation based on crack dynamics
Average fragment size is one of the important parameters characterizing dynamic fragmentation,and the study of the average fragment size is of great significance to reveal the mechanism of rock dynamic fragmentation.Although a lot of theoretical and experimental studies have been conducted by many scholars,the formation mechanism of rock fragmentation has not been revealed from the perspective of crack dynamics.Based on the dynamic crack propagation model of wing cracks and Gladden's dynamic column buckling instability model,we purpose a method to predict the average fragment size under dynamic loading.The effect of strain rate on the dynamic strength and average fragment size is studied.The results show that with the increase of strain rate,the dynamic strength increases,and the average fragment size and strain rate dependence decrease gradually.The prediction of the average fragment size by the proposed model is in good agreement with the experimental data.
rock mechanicsdynamic fragmentationcrack propagation modelbuckling instabilityaverage fragment sizestrain rate