A path dependent constitutive model for CFFT column
A path dependent constitutive model for CFFT column
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DOI：
10.1016/j.engstruct.2020.110367
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发表时间：
2020-05
影响因子：
5.5
通讯作者：
J. Ho;X. Ou;Man-Tai Chen;Qing Wang;M. Lai
中科院分区：
文献类型：
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作者：
J. Ho;X. Ou;Man-Tai Chen;Qing Wang;M. Lai
空心钢管（HST）和纤维增强聚合物（FRP）管等约束不仅可以提高混凝土结构的承载能力，而且可以提高混凝土结构的延性。与HST相比，FRP管具有更强的抗弯和抗拉强度，以及抗腐蚀能力。它也更轻，更耐用。因此，CFFT柱是新建建筑的理想选择，可以提高安全性，延长设计寿命，增强可持续性。然而，他们的实验研究相对有限，现有的应力-应变模型不能捕捉到它们的全范围行为。为了更深入地了解和模拟CFFT柱的单轴性能，收集了28根CFFT柱的试验结果数据库，建立了新的应力-应变模型，该模型包括以下4部分：(1)考虑混凝土劈裂裂缝影响的环向应变模型；(2)考虑围应力路径依赖效应的主动约束混凝土调整本构模型；(3) FRP管的双轴应力模型；(4)混凝土与FRP管的相容性模型。最后，理论轴向应力-应变曲线与CFFT柱试验曲线吻合较好，验证了模型的有效性。
Confinement, such as hollow-steel tube (HST) and fibre-reinforced polymer (FRP) tube, can improve not only the loading capacity of concrete structures, but also ductility. Compared with HST, FRP tube has stronger flexural and tensile strength, as well as resistance against corrosion. It is also lighter and more durable. Thus, concrete-filled-FRP-tube (CFFT) column is ideal for new buildings’ construction for improving safety, prolonging design life and enhancing sustainability. However, their experimental studies are relatively limited, and the existing stress-strain models cannot capture their full range behaviour. Herein, to understand more thoroughly and simulate the uni-axial performance of CFFT columns, a database collecting 28 CFFT columns test results is assembled for establishing a new stress-strain model that comprises the following 4 parts: (1) A model of hoop strain set up by the authors taking into account the effects of concrete splitting cracks; (2) An adjusted constitutive model of actively confined concrete incorporating confining stress path dependent effect; (3) Bi-axial stress model of FRP tube; (4) A model addressing the compatibility condition of concrete and FRP tube. Finally, the theoretical axial stress-strain curve matches very well with those experimental curves of CFFT columns, which verifies the validity of the model proposed in this study.