纤维混凝土界面应力传递机制的三维弹性分析

3-D elastic analysis of stress transference mechanism at the interfaces in fiber reinforced concrete

采用Love位移函数法分析了纤维拔出问题中粘结段的界面应力传递机制。建模时避免了传统模型不精确的假设,对整个粘结段直接进行三维弹性分析,获得了收敛性较好的解。分析结果表明,纤维和基体的应力及位移均为变量,且在界面上存在法向应力突变现象。将计算结果与传统模型的解进行对比,发现两者在界面剪应力和截面平均拉应力分布上也存在较明显差别。该模型满足所有平衡条件、连续条件和大部分边界条件,可用于检验纤维拔出模型的精度和微观力学分析。

The Love displacement function was used to develop a 3-D elastic model to investigate the stress transference mechanism between the fibers and the matrix in the bonding region of reinforced concrete. The stress field in the entire bonding region was obtained directly with good convergence by avoiding inexact assumptions in previous methods. The results show that the stress and the displacement in both the fiber and the matrix vary with the normal stresses changing dramatically near the interface. The distribution of the interfacial shear stress and the average normal stress predicted by this model differ significantly from the predictions of traditional models. The model solutions satisfy all the equilibrium equations, continuity and most of the boundary conditions, so they can be used to analyze the micromechanics and to evaluate the precision of fiber pullout models.