摘要:
深部资源开采与利用过程中的共性科学基础是深部岩石力学理论,准确掌握研究深部岩石动态力学性能,不仅有助于深入理解地球内部的地质过程和演化,还为深部矿产、能源的有效开采提供理论依据。本研究以三维霍普金森杆实验结果为基准,以某煤矿下白砂岩作为研究对象,采用三种典型岩石本构模型(RHT本构模型(Riedel-Hiermaier-Thoma,RHT)、HJC本构模型(Holmquist-Johnson-Cook,HJC)、CSCM本构模型(Clay-Structure-Coupling-Model,CSCM))进行仿真分析,对白砂岩在单轴、双轴和三轴状态下的动态力学性能进行对比与验证。结果表明白砂岩试件的剪切破坏损伤随预应力的增加而降低,三轴状态下岩石受到的损伤明显低于单轴和双轴状态下岩石的损伤;基于RHT本构模型的仿真在应力波波形、峰值应力、峰值应变以及损伤程度上,与实验结果更贴合:单双轴状态下RHT本构模型反射波段的波峰应力偏差率分别为3.5%和13.6%,透射波段的波峰应力偏差率最低,且峰值应力与应变在数值上更接近实验数值。RHT本构模型的损伤状态与实验的损伤状态相似,单轴下呈现U字形损伤特征,HJC本构模型在单轴下则呈现出大范围V字形损伤特征,且发生断裂,CSCM本构模型仅在表面发生损伤,损伤范围较小;在能量吸收和耗散方面三种本构模型差异性较小,三种本构模型的入射能量、反射能量和透射能量基本保持一致。
Abstract:
The common scientific foundation in the process of resource exploitation and utilization is deep rock mechanics theory. Accurately understanding the dynamic mechanical properties of deep rocks not only provides insights into the geological processes and evolution of Earth's interior, but also offers a theoretical basis for the effective extraction of deep minerals and energy. In this study, the dynamic mechanical behavior of white sandstone from a coal mine was experimentally and numerically analyzed under uniaxial, biaxial, and triaxial stress conditions. A comparative analysis was conducted using numerical simulations based on three representative constitutive models (the Riedel-Hiermaier-Thoma (RHT) model, the Holmquist-Johnson-Cook (HJC) model, and the Clay-Structure-Coupling Model (CSCM)). These simulations were validated by experimental results obtained from three-dimensional Hopkinson bar tests. The results indicate that the shear failure damage of white sandstone specimens decreases with the increasing prestress, and the damage under triaxial stress conditions is significantly lower than that under uniaxial and biaxial conditions. Among the three models, the RHT constitutive model demonstrates the closest agreement with the experimental results in terms of stress waveforms, peak stress, peak strain, and damage degree. Compared to the experimental data, the RHT model exhibits a stress peak deviation rate of 3.5% and 13.6% for the reflected wave under uniaxial and biaxial conditions, respectively, while the stress peak deviation rate for the transmitted wave is the lowest. Additionally, the peak stress and strain values predicted by the RHT model are numerically closer to the experimental results. The damage state predicted by the RHT model also aligns well with the experimental observations: under uniaxial loading, the damage exhibits a U-shaped pattern, which the HJC model shows a larger V-shaped damage pattern and fracture, and the CSCM model only displays surface damage with a smaller affected area. In terms of energy absorption and dissipation, the simulation results based on the three constitutive models shows minimal differences. The incident, reflected, and transmitted energy values are nearly identical across all three models.