邱薛,刘晓辉,胡安奎,等. 煤岩动态RHT本构模型数值模拟研究[J]. 煤炭学报,2024,49(S1):1−13. doi: 10.13225/j.cnki.jccs.2023.0540
引用本文: 邱薛,刘晓辉,胡安奎,等. 煤岩动态RHT本构模型数值模拟研究[J]. 煤炭学报,2024,49(S1):1−13. doi: 10.13225/j.cnki.jccs.2023.0540
QIU Xue,LIU Xiaohui,HU Ankui,et al. Research on numerical simulation of coal dynamic RHT constitutive model[J]. Journal of China Coal Society,2024,49(S1):1−13. doi: 10.13225/j.cnki.jccs.2023.0540
Citation: QIU Xue,LIU Xiaohui,HU Ankui,et al. Research on numerical simulation of coal dynamic RHT constitutive model[J]. Journal of China Coal Society,2024,49(S1):1−13. doi: 10.13225/j.cnki.jccs.2023.0540

煤岩动态RHT本构模型数值模拟研究

Research on numerical simulation of coal dynamic RHT constitutive model

  • 摘要: 利用ANSYS/LS-DYNA有限元软件和岩石RHT损伤本构模型对四川宜宾芙蓉白胶煤岩展开不同应变率下煤岩SHPB动态压缩数值模拟试验。首先,依据相关岩石RHT本构模型参数确定方法与Riedel混凝土RHT参数值,通过不同动态应变率下的3水平27组正交试验与13个不确实性参数敏感性分析确定出煤岩RHT动态压缩本构模型最优参数。其次,依据数值模拟试验与室内试验对比分析,发现两种试验所得应力应变曲线能够较好吻合,数值模拟试验结果满足SHPB压缩试验中的一维应力与应力均匀性两个假定,数值模拟试验具有一定的可靠性。最后,利用RHT损伤本构模型探究煤岩动态力学性质及渐近变形破坏过程中的能量演化规律。研究结果表明:RHT损伤本构模型能够较好地模拟煤岩动态变形破坏过程,相应力学特性、能量演化过程与室内试验具有较好一致性;煤岩RHT模型参数随应变率增加呈增大趋势,但敏感性具有差异性,应变率从29.12 s−1增大至95.69 s−1,RHT参数gc*Nft*npco对煤岩最终模拟效果优劣情况值抗压强度最为敏感,而参数pcoξfs*pcoQ0则最不敏感;煤岩抵抗变形能力随应变率增加明显增强,破碎程度愈加剧烈,峰动态强度因子值均呈指数函数增长;依据煤岩动态能量演化过程明显阶段性进行动态特征应力划分,发现特征能量均呈先增大后减小、再趋于稳定的趋势,动态弹性能储存能力和极限储能能力均随应变率增加而增强。

     

    Abstract: Using ANSYS/LS-DYNA finite element software, a rock RHT damage constitutive model is used to conduct numerical simulation experiments on the dynamic compression of coal SHPB under different strain rates for the Furong Baijiao coal in Yibin, Sichuan. Firstly, based on the determination method of RHT constitutive model parameters for relevant rocks and the RHT parameter values for Riedel concrete, the optimal parameters of the coal RHT dynamic compression constitutive model are determined through 3 levels of 27 sets of orthogonal experiments under different dynamic strain rates and sensitivity analysis of 13 uncertainty parameters. Secondly, based on the comparison and analysis of numerical simulation experiments and indoor experiments, it is found that the stress-strain curves obtained from the two types of experiments were in good agreement. The numerical simulation test results meet the two assumptions of one-dimensional stress and stress uniformity in SHPB compression test, and the numerical simulation test has a certain degree of reliability. Finally, the RHT damage constitutive model is used to explore the dynamic mechanical properties of coal energy evolution law during the asymptotic deformation and failure process: The research results indicate that the RHT damage constitutive model can better simulate the dynamic deformation and failure process of, and the corresponding mechanical properties and energy evolution process are consistent with the laboratory tests; The RHT model parameters of coal show an increasing trend with the increase of strain rate, and the sensitivity is greatly different. As the strain rate increases from 29.12 s−1 to 95.69 s−1, RHT parameters gc*Nft*n and pco are most sensitive to the final simulation effect of coal, while the parameters pcoξfs*pco and Q0 are the least sensitive; With the increase of strain rate, the resistance to deformation of coal is obviously enhanced, the degree of fragmentation is more intense, and the peak compressive strength and dynamic strength factor DIF value increase exponentially; The dynamic energy evolution process of coal has obvious stages. Dynamic characteristic stress division based on the obvious stages of dynamic energy evolution process of coal. It is found that the corresponding characteristic energy increases first, then decreases, and then tends to be stable. The dynamic elastic energy storage capacity and limit energy storage capacity of coal should also be enhanced with the increase of strain rate.

     

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