岩石非线性黏弹塑性蠕变模型研究

Study on nonlinear viscoelasto-plastic creep model of rock

提出一种新的非定常粘滞系数的流变元件,然后将提出的非线性流变元件引进到PoytingThomson模型中,从而建立了新的非线性黏弹塑性流变模型,该模型不但可以较好地模拟岩石蠕变三个阶段,而且模型参数较少。推导出模型的本构方程及蠕变方程,并探讨了模型参数的辨识方法,最后利用本文建立的非线性流变模型所得到的理论曲线与砂岩蠕变试验曲线进行对比分析。结果表明:本文建立的非线性流变模型具有较高的准确性及合理性。

In this paper,a new rheological component with unsteady viscous coefficient is proposed,then connecting the proposed nonlinear rheological component with the Poyting-Thomson model,a new nonlinear viscoelastic-plastic rheological model is established.The model can not only simulate the three stages of rock creep,but also has less model parameters.In this paper,the constitutive equation and creep equation of the model are deduced,and the identification method of the model parameters is discussed.Finally,the theoretical curves obtained by the nonlinear rheological model established in this paper and the sandstone creep test curves is compared and analyzed.The results show that the nonlinear rheological model established in this paper has good accuracy and rationality.