金浏, 苏晓, 杜修力. 钢筋混凝土梁受弯破坏及尺寸效应的细观模拟分析[J]. 工程力学, 2018, 35(10): 27-36. DOI: 10.6052/j.issn.1000-4750.2017.06.0436
引用本文: 金浏, 苏晓, 杜修力. 钢筋混凝土梁受弯破坏及尺寸效应的细观模拟分析[J]. 工程力学, 2018, 35(10): 27-36. DOI: 10.6052/j.issn.1000-4750.2017.06.0436
JIN Liu, SU Xiao, DU Xiu-li. MESO-SCALE SIMULATIONS ON FLEXURAL FAILURE AND SIZE EFFECT OF REINFORCED CONCRETE BEAMS[J]. Engineering Mechanics, 2018, 35(10): 27-36. DOI: 10.6052/j.issn.1000-4750.2017.06.0436
Citation: JIN Liu, SU Xiao, DU Xiu-li. MESO-SCALE SIMULATIONS ON FLEXURAL FAILURE AND SIZE EFFECT OF REINFORCED CONCRETE BEAMS[J]. Engineering Mechanics, 2018, 35(10): 27-36. DOI: 10.6052/j.issn.1000-4750.2017.06.0436

钢筋混凝土梁受弯破坏及尺寸效应的细观模拟分析

MESO-SCALE SIMULATIONS ON FLEXURAL FAILURE AND SIZE EFFECT OF REINFORCED CONCRETE BEAMS

  • 摘要: 钢筋混凝土构件破坏的尺寸效应取决于混凝土材料的非均质性以及钢筋/混凝土相互作用。该文借助混凝土细观结构特征,基于非线性弹簧单元来描述钢筋与混凝土之间的相互作用,建立了钢筋混凝土梁破坏行为模拟的三维细观数值模型。在模拟结果与试验结果吻合良好的基础上,拓展模拟了更大尺寸梁的弯曲大变形破坏行为,并分析了单调及循环加载模式对不同尺寸悬臂梁受弯破坏及名义抗弯强度影响规律。模拟结果分析表明:1)该文工况下钢筋混凝土悬臂梁的弯曲破坏存在尺寸效应,弯曲强度随梁深增大而减小; 2)循环加载下,混凝土、钢筋以及两者间的粘结性能由于低周疲劳而使得梁的弯曲破坏呈现出脆性特征; 3)相比于单调加载,循环加载条件下,悬臂梁的破坏具有更强的脆性,名义抗弯强度尺寸效应更明显。

     

    Abstract: The sources of size effect on RC members are the heterogeneity of concrete material and the interaction between steel and concrete. From the view of microcosmic, a three-dimensional micromechanical model for reinforced concrete beams was set up. In the model, the concrete heterogeneity was considered, and the interactions between steel and concrete was described by a nonlinear spring element. Base on the well agreement between simulation results and experimental results, the failure behavior of large beams was studied, meanwhile, the change of failure pattern and flexural strength of different size beams under monotonic and cyclic loading were analyzed. The simulation results show that:1) in the working condition of this article, the flexural of RC cantilever beams have the size effect, and the flexural strength decreases with the increase of depth of the beam; 2) under cyclic loading, the bending beam is brittle because of the fatigue of the bonding performance between concrete and steel; 3) compared to monotonic loading, the cantilever beam damage is more brittle and the size effect of nominal flexural strength is more obvious under a cyclic loading condition.

     

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