无烟煤单轴冲击动态强度理论

摘要

Based on the existent investigations that the main failure pattern of anthracite under uniaxial impact loading is the combined damage of tensile stress damage,extensible strain damage and unloading damage,but compression-shearing damage is infrequent,a compression-extension-tension damage model was proposed to analyze the impact-induced fracture in anthracite.And according to the energy balance principle and the fracture theory,the theoretical formula for calculation of the dynamic strength in the proposed model was deduced to determine the quantitative relationship between the related dynamic parameters of anthracite.A series of compressive strengths of anthracite were calculated by the deduced formula.Comparisons show that the calculated results are in agreement with the existent measured ones.So the deduced formula can be used to estimate the extreme strength of anthracite under uniaxial impact loading and it can reveal the damage mechanism of anthracite-like porous media under impact loading.%根据无烟煤破坏以拉应力破坏、张应变破坏和卸载破坏等组合形式为主、压剪破坏出现的几率很小的特征,提出了无烟煤的压缩膨胀拉伸破坏模型,并在能量平衡原理和断裂理论的基础上,推导了该模型的动态强度理论计算关系式,确定了动力学参数之间的定量关系.利用导出的强度公式,对无烟煤的抗压强度进行了计算,计算结果与已有的实验结果较好吻合.这表明,该公式能够用来预测无烟煤在单轴冲击载荷作用下的极值强度,揭示无烟煤这种多孔隙介质在冲击载荷作用下的破坏机理.