| It's very important step to remove cobalt-rich crusts in mining. So finding a proper way for it is a significant precondition in crash cobalt-rich crusts exploitation.the dissertation was making the condition of cutting force of cobalt-rich crusts vibration cutting removal in vibration and in no-vibration.From the point of view of fracturing mechanism combined with the dynamic stress-strain model and doing the SHPB(Split Hopkinson Pressure Bar) experimentation, the author found the relation of dynamic stress-strain of simulate material of cobalt crusts under impact loading, and built dynamic constitutive model in theory which provided references to material model in simulation experiment. Then the author in review of fracturing dynamics and rock dynamic fracturing rule, analyzed the effect of cobalt crusts' crack propagation under the impact loading, and concluded that which areas of frequency of stress wave took part in crack propagation when the energy action density got the value of threshold. Also the author analyzed the movement process, and established dynamic model of vibration cutting from which we got the bigger force F_v ,the better effective in cutting. On base of that, we did simulation experiment for understanding the condition of cutting force using Ansys/LS-DYNA in any case. According to the conclution of the simulation experiment, A vibration cutting test of forces was carried out on a self-made rock vibration cutting test-bed by octagonal ring dynamometer. The rotary cutting and line cutting were used in my experiment research. The curve of cutting force in any case was studied in this article. And we found that the wave of the vibration cutting force was more peaceful than the static's,and the value of the vibration cutting force was smaller than the others'.Finally, through changing depth and frequency , comparing the simulation result and the testing experiment result, This obtained the testing results coincided with simulation experiment results. |
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