改进宾汉姆流变模型及其参数辨识

传统宾汉姆流变模型不适于描述岩石蠕变的非线性衰减和加速阶段.本文提出一种非线性的改进模型，引入作用函数表征衰减蠕变阶段，引入非线性黏性元件与传统模型串联表征岩石的加速蠕变阶段.通过对绿片岩和砂岩蠕变实验数据进行非线性拟合得到模型参数，与实验曲线的对比分析表明了改进的效果及改进模型的合理性.

IMPROVED BINGHAM RHEOLOGICAL MODEL AND ITS PARAMETER IDENTIFICATION

The nonlinear attenuation and acceleration creep stage of the rock cannot be well described by the traditional Bingham rheological model, which is valid in the stable stage. So, an action function and a nonlinear viscous element are added to characterize the two stages, which transform the traditional linear formulation into a nonlinear one, in the form of an improved Bingham model. The green rock and sandstone creep experimental data are obtained by rheological tests and the parameters of the model are obtained by a nonlinear fltting method. Compared the theoretical curves with the experimental curves, the results show that the improved model is efiective and rational.