箍筋约束混凝土方柱轴压破坏尺寸效应细观数值研究

发布时间：2018-09-04 16:24

【摘要】：钢筋混凝土构件尺寸效应行为源于混凝土材料的非均质性及钢筋/混凝土复杂的非线性相互作用.通过建立反映上述特征的约束混凝土方柱3D细观数值模型,开展轴心受压破坏行为及尺寸效应数值研究,探讨体积配箍率对箍筋约束混凝土方柱轴心受压力学行为及尺寸效应的影响机理,并与试验结果进行对比分析.基于Baznt尺寸效应律,开展约束混凝土轴心抗压强度尺寸效应理论分析.研究结果表明:数值模拟与试验结果吻合良好,构建的钢筋混凝土柱细观力学模型能够准确地描述箍筋约束混凝土构件的破坏行为及尺寸效应规律;体积配箍率增加,约束混凝土柱的名义强度增大、破坏呈现更少的脆性,尺寸效应现象减弱;Baznt尺寸效应理论能够对约束混凝土柱轴心加载下的尺寸效应行为做出合理解释.
[Abstract]:The size effect behavior of reinforced concrete members originates from the heterogeneity of concrete material and the complex nonlinear interaction between steel and concrete. Through establishing 3D mesoscopic numerical model of confined concrete square column reflecting the above characteristics, the numerical study of axial compression failure behavior and size effect is carried out. The influence mechanism of volume hoop ratio on axial compression behavior and size effect of concrete square column confined by stirrups is discussed, and the results are compared with the experimental results. Based on the size effect law of Baznt, the size effect of axial compressive strength of confined concrete is analyzed theoretically. The results show that the numerical simulation is in good agreement with the experimental results. The meso-mechanical model of reinforced concrete columns can accurately describe the failure behavior and size effect of concrete members confined by stirrups, and the volume hoop ratio increases. The nominal strength of confined concrete columns increases, the failure presents less brittleness, and the size effect phenomenon weakens. Baznt size effect theory can reasonably explain the size effect behavior of confined concrete columns under axial loading.
【作者单位】：防灾科技学院防灾工程系;北京工业大学城市减灾与防灾防护教育部重点实验室;
【基金】：国家自然科学基金(批准号:51408127);国家自然科学基金创新研究群体项目(编号:51421005) 防灾科技学院教育研究与教学改革项目(编号:JY2016B07)资助
【分类号】：TU528

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