煤岩组合体破坏行为的能量非线性演化特征

利用MTS 815试验机对煤岩组合体进行单轴和循环加卸载试验,研究了煤岩组合体的能量演化特征及规律。试验结果表明:输入能密度与应力关系可分为3个阶段,即缓慢增长阶段、非线性增长阶段、峰后跌落阶段;单轴压缩下输入能密度和弹性能密度均随着应力的增大而增大,耗散能密度与应力关系比较复杂,其增长率逐渐减小,并趋于0,而后迅速增大,体现出明显的非线性特征;循环加卸载下输入能密度、弹性能密度和耗散能密度随着应力的增大而增大。当试样发生屈服时,耗散能比例增加,弹性能比例降低;研究结论为煤矿动力灾害的能量驱动机制提供一定的理论参考。

Energy Nonlinear Evolution Characteristics of the Failure Behavior of Coal-rock Combined Body

Testing machine MTS 815 was applied to carry out uniaxial compression and cyclic loading-unloading compression for coal-rock combined body.Energy evolution characteristics of different coal-rock combined body were studied.The results show that the relation curves of input energy density and stress have three phases,namely gradually increase phase,nonlinear increase phase and post-peak drop phase.Input energy density and elastic energy density under uniaxial compression increase with the increase of stress.The relationship between the dissipated energy density and stress is complicated.Firstly,increasing rate decreases gradually and tends to be 0.Then,it grows rapidly showing an obvious nonlinear property.Under cyclic loading-unloading compression,energy density shows apparently nonlinear properties.Elastic energy ratio and dissipated energy ratio were calculated and got the relation curves between the ratio and stress.When the specimen yields,the dissipated energy ratio increases and elastic ratio decreases.The conclusions provide a theoretical reference for energy driving mechanism of dynamic disaster in coal mine.