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| Fracture experiments and numerical simulation of cracked body in rock-like materials affected by loading rate |
| LUO Ke,ZHAO Guodong,ZENG Jiajun,ZHANG Xuxu,PU Chengzhi |
| (School of Nuclear Resources Engineering,University of South China,Hengyang,Hulan 421001,China) |
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Abstract To investigate the influence of loading rate on the strength and deformation of rock,we analyzed the fracturing characteristics of rock containing cracks with various inclination angles under various loading rates. Uniaxial compression tests under various loading rates on the prefabricated rock specimens,containing cracks with various inclination angles,were conducted using the testing system RMT–150B. The results show that the peak strains correlate negatively to the loading rates when the static load is applied. For the samples with the same inclination angle,the rock strength increases nonlinearly with the increasing of loading rate. For the samples under the same loading rate,the inclination angle affects the peak strength,and the sample having the crack with the inclination angle of 15° has the lowest strength. The elastic modulus increases nonlinearly firstly with the increasing in the loading rate and inclination angle,then,the elastic modulus remains constant. To monitor the micro patterns of the cracks,numerical modelling of the laboratory tests was carried out with the Flat-jointed bond contact elements in PFC2D. The deformation and damage data of intact specimens were used to determine the values of parameters for numerical analysis. The numerical results of cracked samples agree well with the ones from laboratory tests. The numerical results show that high stress concentration occurs at the crack tips of the sample with the inclination angle of crack of 15°.
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