Numerical Simulation And Experimental Research On Rock Fragmentation Under Dynamic-Static Combined Loads

The fracture is a complex nonequilibrium and nonlinear evolution process. Many scholars engaging in research on rock mechanics have investigated the performances of rocks experiencing static load and dynamic load, obtained many results, and made great progress on both rock mechanics theories and applications. However, the questions on hard rock fragmentation under dynamic-static combined loads with many fracturing patterns are still not solved. Thereby the numerical simulation and experimental research on rock fragmentation under dynamic-static combined loads are primarily set forward.Based on summing and analyzing the characteristics of rock fragmentation using damage fracture mechanics analyze rock fragmentation under uni-static, uni-dynamic loads and dynamic-static combined loads. It could be found that the infect extension by the cutter to rock under uni-static loads is larger than that under impact loads; the middle crack spread fastest in the rock under impact load.In order to study the influence of microstructure characteristic on the macroscopic mechanical behavior and fracture mechanism, rock fragmentation was numerical simulated under uni-static, uni-dynamic loads and coupling static and dynamic loads. It could be found that the infect extension by the cutter to rock under uni-static loads is larger than that under impact loads; the middle crack spread fastest in the rock under impact load; the depth , area and comprehensivel effects of rock fragmentation under combined loads are better than that under uni-static or uni-dynamic loads by analyzing the distributing chart of stress, displacement and crack in the rock.The rock fragmentation under uni-static, uni-dynamic loads and coupling static and dynamic loads were experimented in the multifunctional device. Through the experiment results show that rock fracture effect can not great enhancement by single increase uni-static or uni-dynamic loads; fragmentation effects of rock under coupling dynamic and static loads have more obvious advantages than that of uni-impacting or uni-static pressure; the reasonable ratio of dynamic load to static load may make the specific energy consumption of rock fragmentation least and fracture effect optimal. Results show that experimental research, theoretical analysis and numerical simulation obtain the same conclusion, which verify the accuracy of theoretical analysis and reliability of numerical simulation.