Cyclic modeling of FRP-confined concrete with improved ductility
Cyclic modeling of FRP-confined concrete with improved ductility
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DOI：
10.1016/j.cemconcomp.2006.07.009
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发表时间：
2006-11
影响因子：
10.5
通讯作者：
Y. Shao;Z. Zhu;A. Mirmiran
中科院分区：
文献类型：
--
作者：
Y. Shao;Z. Zhu;A. Mirmiran
纤维增强复合材料（FRP）约束混凝土柱可以显著提高柱的强度和延性。FRP约束混凝土的单轴压缩性能可以用其应力-应变双线性和独特的膨胀特性来表征。近年来，已经开发了一些模型来捕捉单调加载下的这些特性。然而，没有解决的循环响应FRP约束混凝土。对24根FRP约束混凝土短柱进行了不同加载和卸载水平、不同纤维类型、不同缠绕厚度和不同加载方式的单轴压缩试验。基于试验结果的回归分析，本构模型的开发，包括循环规则的加载和卸载，塑性应变，刚度和强度退化。所提出的模型进行了验证，通过比较分析预测与实验结果的一个独立的测试系列。分析和实验结果吻合较好，证实了该模型预测FRP约束混凝土循环性能的能力。该模型可以很容易地实现在纤维单元模型的弯曲分析的循环加载梁-柱结合应变梯度法。
Confinement by fiber reinforced polymer (FRP) wraps can significantly enhance strength and ductility of concrete columns. Behavior of FRP-confined concrete in uniaxial compression can be characterized by its bilinear stress–strain and unique dilation properties. A number of models have in recent years been developed to capture these characteristics under monotonic loading. None, however, have addressed the cyclic response of FRP-confined concrete. A total of 24 FRP-confined concrete stub specimens were tested in uniaxial compression under different levels of loading and unloading, with different fiber type, wrap thickness, and loading patterns. Based on a regression analysis of test results, a constitutive model is developed that includes cyclic rules for loading and unloading, plastic strains, and stiffness and strength degradations. The proposed model is validated by comparing analytical predictions with experimental results of an independent test series. Good agreement was shown between the analysis and experiments, confirming the ability of the model to predict the cyclic behavior of FRP-confined concrete. The model could be easily implemented in a fiber element model for flexural analysis of cyclic loaded beam-columns in conjunction with a strain gradient approach.