突出煤的冲击力学行为及本构关系的研究

Research on Impact Mechanical Behavior and Constitutive Relation of Outburst Coal

为了探索突出煤在冲击载荷作用下的破坏变形特征和动态本构关系,采用75mm分离式霍普金森压杆(SHPB)对淮南矿区B6煤层突出煤进行了不同冲击速度下的单轴冲击压缩实验,并结合现有的岩石类材料的本构模型,构建了反映突出煤动态力学特性的本构方程。研究结果表明:突出煤在冲击载荷作用下的破坏变形过程大体可概括为初始非线性阶段、屈服阶段、应变强化阶段和卸载破坏阶段4个阶段;所构建的包含损伤效应和应变率效应的动态本构方程能较好地反映突出煤在峰值应力前的动态应力应变关系。

In order to explore the deformation features and dynamic constitutive relation of outburst coal under impact load,the impact compression test under different strain rate of outburst coal from B6 coal seam in Huainan Coal Mine was carried out by split Hopkinson pressure bar（ SHPB） of 75 mm in diameter. Combined with the existing constitutive model of rock material,a new dynamic constitutive equation for outburst coal has been proposed. The test result shows that the whole deformation process of outburst coal under impact load includes four stages basically： the initial nonlinear stage,yield stage,strain-hardening stage and unloading damage stage; and the fitted dynamic constitutive equation including damage effect and strain rate effect can fit dynamic stress-strain relationship of outburst coal before peak stress.