岩石分数阶蠕变损伤本构模型研究

Study on Constitutive Model of Fractional Creep Damage of Rock

红层边坡蠕滑现象显著,岩石具有较强的蠕变特性。为了反映岩石蠕变全过程,基于岩石蠕变的阶段特征,通过弹性体、基于分数阶微积分的软体元件和黏塑性体来分别描述岩石蠕变的弹性应变、黏弹性应变和黏塑性应变。将损伤变量加入弹性体,引入SN元件改进分数阶软体元件,综合改进后的考虑时效损伤的弹性体和基于分数阶微积分的非定常黏滞体和黏塑性体,构建新的三元件蠕变损伤本构模型。采用RLW-2000三轴流变试验系统开展红层泥岩三轴压缩蠕变试验,再引用相关文献中盐岩和红砂岩典型蠕变数据,通过三种岩石蠕变曲线对该模型进行验证,证明所建模型的合理性和适用性。

The creep of the red layer side slope is remarkable,and the rock has strong creep characteristics. In order to reflect the whole process of the rock creep,the elastic strain,the viscoelastic strain and the viscoplastic strain of the rock creep were respectively described by the elastic body,the soft element based on the fractional calculus and the viscoplastic body based on the phase characteristic of the rock creep. The damage variable was added to the elastomer,the SN element was introduced to improve the fractional-order soft element,the modified elastomer and the non-unsteady viscous body and the viscoplastic body based on the fractional calculus were integrated,and a new constitutive model of the three-element creep damage was constructed. The triaxial compression and creep test of red-layer mudstone is carried out by the RLW-2000 three-axis rheological test system,and the typical creep data of the red and red sandstone in the relevant literature are cited,and the model is verified by three kinds of rock creep curves,and the rationality and applicability of the model are proved.