【摘要】 为了探究在循环荷载下岩石的疲劳变形特性,本文基于分数阶微积分构建了非定常疲劳分数阶黏塑性体,利用其替换传统西原模型中的黏塑性体,然后对引入的裂隙塑性体进行改进。最后,将非定常疲劳分数阶黏塑性体、改进的裂隙塑性体与广义Kelvin体串联,构建了一维和三维新型分数阶黏弹塑性体疲劳本构模型。对已有的岩石疲劳试验结果拟合表明:经过改进后的西原模型,对于循环荷载下的减速、等速以及加速3个岩石疲劳变形的阶段可以较好地描述,同时也较好体现了循环荷载下裂隙对岩石变形的影响。更多还原

【Abstract】 In order to study the fatigue deformation characteristics of rock under cyclic loading,a non-definite fatigue fractional visco-plastic element was constructed based on fractional calculus theory. Firstly,the visco-plastic body in the classical Nishihara model was replaced by a non-definite fatigue fractional visco-plastic element. Then the fractured plastic element was introduced and modified. Finally,the modified fractured plastic element and a non-definite fatigue fractional visco-plastic element were connected in series with the generalised Kelvin model,1D and 3D new fractional viscoelastic-plastic fatigue constitutive models,which can describe the law of rock deformation under cyclic loading were established. The fitting of the previous rock fatigue test results shows that the modified Nishihara model can well describe the three fatigue deformation stages of deceleration,constant velocity,and acceleration under cyclic loading. At the same time,it also well reflects the influence of joints and cracks on rock deformation under cyclic loading.更多还原