Establishment of damage statistical constitutive model of loaded rock and method for determining its parameters under freeze-thaw condition
Establishment of damage statistical constitutive model of loaded rock and method for determining its parameters under freeze-thaw condition
复制标题
冻融条件下加载岩石损伤统计本构模型的建立及其参数确定方法
DOI：
10.1016/j.coldregions.2019.01.004
复制
发表时间：
2019-04-01
影响因子：
4.1
通讯作者：
Luo, Xuedong
中科院分区：
文献类型：
--
作者：
Fang, Wen;Jiang, Nan;Luo, Xuedong
建立冻融和加载条件下岩石工程材料的通用损伤本构模型，对分析和预测岩石工程材料的变形特性具有重要意义。通过对冻融和加载条件下所建立的统计损伤本构模型的研究，给出了模型参数和应力-应变曲线特征参数的解析表达式，弹性模量、应力和峰值点处的相应应变）。在此基础上，引入了一个符合牛顿材料冷却定律的衰减模型，建立了弹性模量、峰值应力与冻融循环次数之间的关系。再次，通过对应力-应变曲线峰值应变与冻融循环次数的相关性分析，提出了不同冻融循环次数下峰值应变的计算公式。为此，提出了不同冻融循环次数下统一模型参数的确定方法，推广了冻融和加载条件下的统计损伤本构模型，并通过大理岩冻融力学试验验证了模型的合理性。结果表明，在不同冻融循环条件下，该模型所描述的应力-应变曲线与试验曲线吻合较好，特别是在峰值强度点。研究结果可为不同冻融循环下岩石力学性质的研究提供理论参考
It is of great significance to analyze and predict the deformation characteristics of rock engineering materials by establishing a universal damage constitutive model under freeze-thaw and loading conditions. Based on the study of statistical damage constitutive model founded under freeze-thaw and loading condition, analytical expressions of the model parameters and characteristic parameters in the stress-strain curves (i.e., elastic modulus, stress and corresponding strain at the peak point) were established under specific freeze-thaw cycles. Then, an attenuation model that complies with Newton's material cooling law was introduced to develop the relationship among elastic modulus, stress at peak point and freeze-thaw cycles. Thirdly, the formula of the peak strain under different freeze-thaw cycles was proposed by exploring the correlation between the peak strain of stress-strain curves and freeze-thaw cycles. Therefore, the determination method of the unified model parameters under different freeze-thaw cycles is proposed, then, statistical damage constitutive model under freeze-thaw and loading conditions is generalized, and the freeze-thaw mechanics test with marble was performed to verify the rationality of the model. The results show that stress-strain curves described by presented model under different freeze-thaw cycles have a good agreement with the experimental curves, especially at the peak strength point. The results can provide theoretical reference for the study of rock mechanical properties under different freeze-thaw cycles