混凝土单轴受拉断裂行为的近场动力学模拟

混凝土的宏观力学行为取决于材料组成及其性质。本文基于键基近场动力学理论建立了多相非均质性的混凝土细观尺度数值模型,研究了单轴拉伸作用下混凝土的宏观力学性能和断裂过程。通过改变粗骨料含量、砂浆强度、粗骨料强度以及界面过渡区强度对模型合理性进行了验证。结果表明:软化段之前的应力-应变曲线能够被很好重现,能准确描述混凝土在单轴拉伸作用下的力学性能和断裂过程;调整数值模型中各相材料的力学参数能够合理模拟出不同类型的混凝土在单轴拉伸作用下的断裂过程。

Peridynamic Simulation of Concrete Fracture Behavior under Uniaxial Tension

The macroscopic mechanical behaviors of concrete depend on the material composition and its properties. In this paper, a mesoscale numerical model of concrete with multiphase heterogeneity based on the band-based peridynamic theory was established to study the macroscopic mechanical properties and fracture processes of concrete under uniaxial tension. The rationality of the model was verified by varying the content of coarse aggregate, the strength of mortar, the strength of coarse aggregate and the strength of interface transition zone (ITZ). The results show that the stress-strain curves before the softening section can be reproduced well, and the mechanical properties and fracture process of concrete under uniaxial tension can be accurately described. In addition, the fracture process of different types of concrete under uniaxial tension can be reasonably simulated by adjusting the mechanical parameters of each phase materials in the numerical model.