基于内变量热力学的岩石蠕变与应力松弛研究

发布时间：2018-05-15 21:24

本文选题：岩石力学 + 蠕变　；参考：《岩石力学与工程学报》2015年04期

【摘要】：蠕变和应力松弛是岩石材料固有的时效特性,与岩石工程的长期稳定性密切相关。基于Rice不可逆内变量热力学理论对岩石蠕变和松弛本质上的一致性问题进行研究。给定余能密度函数和内变量演化方程建立基本热力学方程,通过不同约束条件构建黏弹黏塑性蠕变和应力松弛本构方程。黏弹性本构方程具有普遍性,能包含经典元件组合模型的黏弹性本构方程;黏塑性本构方程考虑材料变形过程中的硬化效应,更加符合实际情况。蠕变和松弛是岩石材料在不同约束下的外在表现,但两者具有相同的非平衡演化规律,本质上具有一致性。蠕变与应力松弛本构方程基于相同的基本热力学方程,可以相互转化,且方程参数相同,因此可以通过蠕变方程和蠕变试验结果对材料的松弛特性进行分析。最后通过模型相似材料单轴蠕变加卸载试验和应力松弛试验对这一思想进行验证。
[Abstract]:Creep and stress relaxation are inherent aging characteristics of rock materials and are closely related to the long term stability of rock engineering. Based on Rice's theory of thermodynamics of irreversible internal variables, the intrinsic consistency of rock creep and relaxation is studied. Given the complementary energy density function and the evolution equation of internal variables, the basic thermodynamic equations are established, and the viscoelastic viscoplastic creep and stress relaxation constitutive equations are constructed by different constraint conditions. The viscoelastic constitutive equation is universal and can include the viscoelastic constitutive equation of the classical element combination model, and the viscoplastic constitutive equation considers the hardening effect in the process of material deformation, which is more in line with the actual situation. Creep and relaxation are the external performances of rock materials under different constraints, but they have the same law of non-equilibrium evolution and are consistent in nature. The creep and stress relaxation constitutive equations are based on the same basic thermodynamic equations and can be transformed into each other with the same parameters. Therefore, the relaxation properties of the materials can be analyzed by the creep equation and the creep test results. Finally, uniaxial creep loading and unloading tests and stress relaxation tests are used to verify this idea.
【作者单位】：清华大学水沙科学与水利水电工程国家重点实验室;
【基金】：国家自然科学基金资助项目(51279086) 清华大学水沙科学与水利水电工程国家重点实验室科研课题资助(2013 KY 2) 新世纪优秀人才支持计划资助(NCET 13 0323)
【分类号】：TU45

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