摘要
采用OpenSees有限元程序建立纤维增强复合材料（fiber-reinforced polymer,FRP）筋混凝土偏压柱非线性分析模型,通过已有试验结果验证了该模型的合理性。基于该模型开展了18 000根FRP筋混凝土（FRP-RC）偏压柱二阶效应的参数分析,主要参数包括材料强度、荷载偏心率、长细比、FRP筋类型和配筋方案等。分析结果表明,我国GB 50010—2010《混凝土结构设计规范》中钢筋混凝土偏压柱的弯矩增大系数低估了FRP-RC偏压柱的二阶效应。通过对参数分析结果的回归分析,得到了FRP-RC偏压柱的弯矩放大系数修正计算公式。此外,基于平衡条件和变形协调条件,推导了FRP-RC柱正截面承载力计算式。结合弯矩放大系数法和正截面承载力计算式,提出了FRP-RC偏压柱承载力计算方法。将收集的国内外43个FRP-RC偏压柱试件承载力试验值与该方法计算值进行了对比,二者吻合良好。
This study presents an investigation on calculating approach of ultimate capacity of FRP-RC columns under eccentric compression. Firstly, a nonlinear finite element model was established using OpenSees for FRP-RC column under eccentric loading. A comparison between experimental and analytical results demonstrates that the presented finite element model could provide good predictions for the responses of FRP-RC columns. Then, a detailed parametric study of 18 000 columns was performed considering various key parameters, such as a material strength, eccentricity ratio, slenderness ratio, type of FRP reinforcement, and longitudinal reinforcement arrangement. The parametric analysis results show that the moment magnification factor for steel RC columns in current Chinese code GB 50010-- 2010 underestimates the second-order effect of FRP-RC columns. Based on a regression analysis of the parametric analysis results, a modified design equation of moment magnification factor was derived to determine the second-order bending moments. Subsequently, design equations were derived to determine the strength of cross section with FRP bars based on the strain compatibility, force equilibrium, and constitutive equations. Finally, combing the moment magnification factor method with the cross section strength, a calculating approach for ultimate capacity of FRP-RC columns under eccentric loading was proposed. The predictions obtained from the proposed approach are found in good agreement with experimental results, by comparing the predictions with available experimental results of 43 columns.
作者
彭飞
薛伟辰
PENG Fei, XUE Weichen(College of Civil Engineering, Tongji University, Shanghai 200092, China)
出处
《建筑结构学报》
EI
CAS
CSCD
北大核心
2018年第10期147-155,共9页
Journal of Building Structures
基金
国家自然科学基金项目(51678433)
中央高校基本科研业务费专项(0200219151)
上海市科委优秀学术带头人项目(16XD1402800)
关键词
混凝土柱
纤维增强复合材料筋
二阶效应
弯矩放大系数
承载力
计算方法
reinforced concrete column
fiber-reinforced polymer bar
second-order effect
moment magnification factor
bearing capacity
calculation approach
