基于复合损伤的节理岩体动态本构模型研究

基于运用霍普金森压杆（SHPB）装置对节理岩体动载试验得出的数据，从节理面倾角、贯通度、厚度、组数、填充物及应变率等不同方面分析各因素对节理岩体力学特性的影响，通过对节理岩体在高应变率下的损伤机制和破坏形式进行分析的基础上，基于复合损伤理论，对广义Bingham模型进行改进，构造了节理岩体材料在不同应变率下动态响应的本构模型，对模型计算和试验结果的比较表明，该模型能够很好地描述节理岩体动荷载下初始弹性变形阶段、稳态塑性变形阶段和加速变形破坏阶段的应力-应变关系，并且理论与试验结果吻合较好，从而证明了该模型的正确性和合理性。

Dynamic constitutive model of jointed rock mass based on the theory of composite damage

Based on the measurements of the spilt Hopkinson pressure bar (SHPB) dynamic tests on the jointed rock mass, we analyze the influence of various factors on the jointed rock mass, including the joint plane angle, penetration degree, thickness, crack group number, fillers and strain rate. By analyzing the mechanism of damage and the mode of failure for the jointed rock mass under high-strain rate, the general Bingham model is modified based on the theory of composite damage, and a constitutive model for modelling the dynamic response of the jointed rock mass under different strain rates is developed. Comparison of the theoretical simulations with the experimental results shows that the model can well describe the stress-strain relationship of the jointed rock mass in the early stage of elastic deformation, the steady stage of plastic deformation and the destruction stage of accelerating deformation under dynamic loading. The theoretical results agree well with the experimental data, showing the capability and good performance of the proposed constitutive model.