ISSN 1000-3665 CN 11-2202/P

    考虑损伤和硬化的岩石单轴加速蠕变本构模型

    Uniaxial accelerated creep constitutive model of rock considering damage and hardening

    • 摘要: 当前关于岩石蠕变的研究已取得一定进展,但在深入理解和准确描述岩石蠕变的非线性特征以及加速蠕变变形规律方面仍存在不足,在考虑岩石在蠕变过程中的损伤和硬化效应时,现有的模型往往无法全面反映这些复杂机制。基于Rabotnov蠕变损伤法则并结合硬化与损伤理论,构建了一种考虑岩石在蠕变过程中损伤和硬化效应的单轴加速蠕变本构模型。结果表明:(1)在破坏应力作用下,岩石的损伤变量随时间先缓慢增大后陡然增大,接近破坏时间时损伤变量达到1。(2)硬化函数的引入证实了蠕变稳定阶段中硬化现象的存在,模型能真实反映岩石的损伤程度和硬化效应。(3)考虑硬化与损伤机制的蠕变本构模型能够准确描述岩石在不同应力下的蠕变行为,相关性系数高于0.90。(4)该模型能较好地预测岩石在破坏应力下的变形规律。研究成果对地下工程围岩稳定和地质灾害防治具有重要意义。

       

      Abstract: Although significant progress has been made in the study of rock creep deformation, major challenges remain in accurately characterizing its nonlinear features and the mechanisms governing accelerated creep. Existing constitutive models often fail to capture these complexities, particularly the coupled effects of damage accumulation and hardening during creep. In this study, a uniaxial accelerated creep constitutive model incorporating both damage and hardening is proposed, based on the Rabotnov creep damage law and combined with hardening and damage theories. The results indicate that under failure stress, the rock damage variable increases slowly at first, then rises sharply, approaching unity at the time of failure. The introduction of a hardening function confirms the presence of hardening phenomena during the creep stabilization stage, accurately characterizing the extent of damage and hardening effects in rocks. The proposed model effectively captures rock creep behavior across different stress levels, with correlation coefficients exceeding 0.90, and the model can reliably predict the deformation patterns of rocks under failure stress. The results are crucial for the stability of surrounding rocks in underground engineering and prevention of geological disasters.

       

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