Mesoscale modelling of concrete tensile failure mechanism at high strain rates
Mesoscale modelling of concrete tensile failure mechanism at high strain rates
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DOI：
10.1016/j.compstruc.2008.04.013
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发表时间：
2008-11-01
影响因子：
4.7
通讯作者：
Hao, H.
中科院分区：
文献类型：
--
作者：
Zhou, X. Q.;Hao, H.
在细观尺度下，混凝土可以看作是由粗骨料、砂浆基体和骨料与砂浆基体之间的界面过渡区（ITZ）组成的三相复合材料。本文采用细观模型分析了混凝土在高应变率下的动态拉伸行为，特别是分析了界面区对破坏特性的影响。在中尺度模型中，为了简化问题，粗骨料的形状被假定为圆形，ITZ区域被建模为骨料周围的薄边界层。采用动态材料特性和连续损伤力学理论模拟了这三个阶段的材料行为。对混凝土试件在不同应变率下受拉过程进行了数值模拟。考虑了不同骨料粒径、不同骨料分布和不同材料性质。还分析了应变率效应。从数值结果中，它被发现，动态破坏（裂纹）模式是高度受骨料分布。研究还发现，界面过渡区的性质对混凝土的破坏机理和抗拉强度有重要影响。(C)2008爱思唯尔有限公司保留所有权利。
At mesoscale, concrete may be regarded as a three-phase composite consisting of coarse aggregate, mortar matrix and interfacial transition zone (ITZ) between the aggregate and the mortar matrix. In the present paper, mesoscale model is adopted to analyze the dynamic tensile behaviour of concrete at high strain rates; especially, the effects of the ITZ on the failure properties are analyzed. In the mesoscale model, to simplify the problem, the shape of the coarse aggregate is assumed to be circular and the ITZ zone is modelled as a thin boundary layer around the aggregate. Dynamic material properties and continuum damage mechanics theory are employed to simulate the material behaviour of the three phases. Numerical simulation of the concrete samples under tension at different strain rates are carried out. Different aggregate size, different aggregate distribution and different material properties are considered. Strain rate effect is also analyzed. From the numerical results, it is found that the dynamic failure (crack) pattern is highly affected by the aggregate distribution. It is also found that the properties of the interfacial transition zone significantly influence the failure mechanism and the tensile strength of concrete. (C) 2008 Elsevier Ltd. All rights reserved.