The study of constitutive relationship and damage degradation is crucial in solving the stability challenges faced in the rock engineering. In this work, the stress-strain relationships of different type of rocks subjected to uniaxial loading processes are investigated in details. Experimental results demonstrate measurements, such as uniaxial compressive strength (UCS), tangent deformation modulus, peak strain, and Poisson’s ratio ([Formula: see text]). A novel piecewise constitutive model is proposed that utilizes both a constitutive model during compaction and a conventional damage model using the strain equivalence assumption and logistic growth theory to represent the characteristics of stress-deformation curves during both compaction and post-compaction stages. The performance of the proposed constitutive models in capturing deformation characteristics of damaged rocks is demonstrated to be more outstanding in comparison to existing models. In all experimental cases discussed in this study, the proposed model outperforms existing reference models in terms of the coefficients of determination ([Formula: see text]), with the former having coefficients of determination greater than 0.95. Furthermore, physical meanings of relevant model parameters are found to be closely associated with properties of experimental stress-strain curves.

中文翻译：

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单轴加载岩石力学损伤特征及新型本构模型

本构关系和损伤退化的研究对于解决岩石工程面临的稳定性挑战至关重要。在这项工作中，详细研究了不同类型岩石在单轴加载过程中的应力-应变关系。实验结果证明了测量结果，例如单轴压缩强度 (UCS)、切线变形模量、峰值应变和泊松比（[公式：参见文本]）。提出了一种新颖的分段本构模型，该模型利用压实过程中的本构模型和使用应变等效假设和逻辑增长理论的常规损伤模型来表示压实阶段和压实后阶段的应力变形曲线特征。与现有模型相比，所提出的本构模型在捕捉受损岩石变形特征方面的性能更加突出。在本研究讨论的所有实验案例中，所提出的模型在决定系数方面优于现有参考模型（[公式：见文本]），前者的决定系数大于0.95。此外，相关模型参数的物理意义与实验应力-应变曲线的性质密切相关。