Zhou Luming, Zhu Shu, Zhu Zhende, Xie Xinghua
Key Laboratory of Ministry of Education for Geomechanics and Embankment Engineering, Hohai University, Nanjing 210098, China.
Jiangsu Research Center for Geotechnical Engineering Technology, Hohai University, Nanjing 210098, China.
Materials (Basel). 2022 Jun 2;15(11):3977. doi: 10.3390/ma15113977.
The propagation and coalescence of cracks in fiber-reinforced concretes (FRCs) is the direct cause of instability in many engineering structures. To predict the crack propagation path and failure mode of FRCs, an orthotropic-bond-based peridynamic (PD) model was established in this study. A kernel function reflecting long-range force was introduced, and the fiber bond was used to describe the macroanisotropy of the FRC. The crack propagation process of the FRC plate with flaws was simulated under uniaxial tensile loading. The results showed that under homogeneous conditions, the cracks formed along the centerline of the isotropic concrete propagate in a direction perpendicular to the load. Under anisotropic conditions, the cracks propagate strictly in the direction of the fiber bond. The failure degree of the FRC increases with the increase in heterogeneity. When the shape parameter is 10 and the fiber bond is 0°, the failure mode changes from tensile to shear failure. When the fiber bond is 45°, the FRC changes from a state where outer cracks penetrate the entire specimen to a state where cracks coalesce at the middle. It was found that the improved model can effectively simulate the crack propagation processes of orthotropic FRC materials.
纤维增强混凝土（FRC）中裂纹的扩展与合并是许多工程结构失稳的直接原因。为了预测FRC的裂纹扩展路径和破坏模式，本研究建立了一种基于正交各向异性粘结的近场动力学（PD）模型。引入了反映长程力的核函数，并采用纤维粘结来描述FRC的宏观各向异性。模拟了含缺陷FRC板在单轴拉伸载荷作用下的裂纹扩展过程。结果表明，在均匀条件下，各向同性混凝土中沿中心线形成的裂纹沿垂直于载荷的方向扩展。在各向异性条件下，裂纹严格沿纤维粘结方向扩展。FRC的破坏程度随不均匀性的增加而增大。当形状参数为10且纤维粘结角度为0°时，破坏模式从拉伸破坏转变为剪切破坏。当纤维粘结角度为45°时，FRC从外部裂纹贯穿整个试件的状态转变为裂纹在中部合并的状态。研究发现，改进后的模型能够有效模拟正交各向异性FRC材料的裂纹扩展过程。
