基于数值试验的FRP约束混凝土圆柱轴压性能研究

纤维增强复合材料(FRP)约束混凝土柱(FRP Confined Concrete Column,简称"FCCC")具有承载力高、延性好等优点,目前以试验为主要研究方法,很难对其截面尺寸、混凝土强度等级及FRP层数等参数进行全面研究。首先对FCCC轴压性能的试验和数值模拟研究现状进行了归纳总结,然后基于Drucker-Prager弹塑性本构建立有限元模型,并通过现有试验结果验证了该模型的正确性;采用该有限元模型研究了截面直径为150 mm~750 mm,混凝土强度等级为C30~C80以及FRP层数为1层至5层的不同FCCC的轴压性能。结果表明:FRP层数恒定时,FCCC的轴向承载力和延性随着混凝土强度等级的提高而分别提高和降低;混凝土强度恒定时,FCCC的轴向承载力和延性随着FRP约束量的增加而提高;混凝土强度和FRP层数恒定时,FCCC的轴向承载力随着直径的增大而减小。通过数值试验的方法较全面地研究了不同参数对FCCC轴压性能的影响,可为FCCC受力性能的进一步研究和工程设计提供参考。

STUDY ON AXIAL COMPRESSION PERFORMANCE OF FRP CONFINED CONCRETE CYLINDER COLUMNS BASED ON NUMERICAL EXPERIEMNTS

Fiber-reinforced Polymer (FRP) Confined Concrete Column (FCCC) have superior axial compressive capacity and ductility.It is difficult to make a comprehensive study about key parameters such as sec tional dimension,concrete strength and number of FRP layer,due to the common approach,specimens experiment.Firstly,FCCC's axial compressive test and simulation were reviewed.Then,a Finite Element (FE) model was created based on Drucker-Prager Constitutive and the validity of the FE model was verified based on the existing experimental results.Then,the axial compressive performance of FRP confined concrete column with different parameters was investigated using the verified FE model.Diameter of section,concrete strength grade and number of FRP layer were selected as key parameters and their ranges were 150 mm ～ 750 mm,C30 ～ C80 and 1 ～5,respectively.The results show that when the layers of FRP are constant,as the strength level of concrete increase,axial strength and ductility increase and decrease,respectively.When the concrete strength are constant,the axial bearing capacity and ductility of FCCC increases with increasing layers of FRP.When constraint amount of FRP and concrete strength are constant,confinement effect of FRP for inner concrete decreases with increasing diameter of section.The comprehensive studies about the effects of different parameters on the axial compression performance of FCCCs in this paper can provide a reference for further research and design of FCCCs.