碳纤维布均匀约束下煤圆柱的损伤演化

Damage Evolution of Coal Cylinder under Uniform Confinement of Carbon Fiber Sheets

煤柱失稳灾害仍然是目前煤炭资源安全高效开采的热点研究问题之一。为深入研究碳纤维布层数和加载速率对煤圆柱能量演化的影响,加载速率分为0.01 mm/min、0.1 mm/min、1 mm/min和10 mm/min 4级,碳纤维布约束层数分为0层、1层和2层3类,采用SAM-2000岩石综合试验系统对煤圆柱进行单轴压缩试验。试验结果表明:相同碳纤维布层数下,加载速率越高,崩飞的煤屑扩散越明显,煤圆柱整体性越差,能量释放程度越强,属于劈—剪复合失效模式;碳纤维布层数越多,峰值总能量、峰值弹性能和峰值耗散能逐渐增加,加载速率对煤圆柱能量方面的影响减小。根据能量耗散理论,提出损伤因子,进而建立了本构模型,经验证拟合度较高。

The coal pillar instability disaster is still one of the hot research issues in the safe and efficient mining of coal resources.In order to further study the influence of carbon fiber sheets layers and loading rates on the energy evolution of coal cylinder.The loading rate is divided into four levels:0.01 mm/min,0.1 mm/min,1 mm/min and 10 mm/min,and the layers number of carbon fiber sheets is divided into three categories:0 layer,1 layer and 2 layers.The SAM-2000 rock comprehensive test system was used to perform uniaxial axial compression test on coal cylinder.The test results show that under the same lay-ers of carbon fiber sheets,the higher the loading rate,the more obvious the diffusion of coal dust,the worse the integrity of the coal cylinder,and the stronger the energy release,which belongs to the split-shear composite failure mode.the more layers of carbon fiber sheets,the total energy,elastic energy and dissipated energy at peak gradually increase,the effect of loading rate on the energy of coal cylinder is reduced.According to the energy dissipation theory,the damage factor is proposed,and then the constitutive model is established,and it has a high degree of fitting with the experimental verification.