考虑蠕变损伤的Q_2黄土流变本构模型

Creep damage rheological constitutional model for Q_2 loess

根据Q2黄土的流变特征,其粘弹性特性可采用五元件广义的Kelvin模型来描述,其线性粘塑性特性可用与一滑块并联的Maxwell模型来描述,而非线性粘塑性特性,可通过损伤与塑性应变的耦合作用来反映。在考虑黄土瞬时损伤、蠕变损伤及黄土粘弹塑性组合模型的基础上,应用应变等效原理,建立了蠕变损伤流变本构模型,并通过拟牛顿法确定了相应的模型参数。该模型能够较好地描述黄土的加速蠕变过程,具参数少、适用性广的特点。

On the basis of rheological properties of Q2 loess,viscoelastic creep phase is simulated by the generalized Kelvin model,linear viscoplastic creep phase is simulated by the Maxwell model which is parallel connected by a slider,and nonlinear viscoplastic creep phase is reflected by couple of damage and plastic strain.The creep damage constitutional model is estabished from hypothesis of strain equivalence,in which instantaneous damage and creep damage are considered.The parameters can be determined by Quasi-Newton methods.The creep damage rheological constitutional model can describe the accelerated rheological stage of loess,and the parameters are less,and the model can be applied to practice well.