基于宏观模型的FRP筋纤维混凝土梁拉伸刚化效应研究  

Investigation of tension stiffening effect in fiber concrete beam reinforced with FRP bars based on macroscopic model

作　　者：安茹 李源康 陈国雄 符师桦 AN Ru;LI Yuankang;CHEN Guoxiong;FU Shihua(School of Civil Engineering and Architecture,Hainan University,Haikou 570228,China)

机构地区：[1]海南大学土木建筑工程学院,海口570228

出　　处：《复合材料科学与工程》2023年第2期67-74,共8页Composites Science and Engineering

基　　金：国家自然科学基金(11802080);海南省自然科学基金(118QN182,520CXTD433)。

摘　　要：在混凝土中添加纤维能有效控制纤维增强聚合物(Fiber Reinforced Polymer, FRP)筋混凝土梁的裂缝宽度并提高梁的延性。本研究结合纤维混凝土受拉本构关系,引入一个减弱系数描述纤维混凝土开裂后的刚度,建立了能够反映FRP筋纤维混凝土梁拉伸刚化效应的三维有限元模型。在不同纤维含量和不同配筋率下,模拟获得了与实验结果一致的荷载-位移响应。此外,有限元分析得到的裂缝形态与实验结果良好吻合,且随着减弱系数的减小,裂缝扩展减缓,极限荷载下裂缝数量增多,宽度减小。研究还表明,减弱系数随纤维含量特征参数的增大而线性减小,其线性斜率受配筋率的影响微弱,而截距受配筋率的影响明显。Adding fiber in concrete can effectively decrease the crack width of FRP reinforced concrete beams and improve the ductility of the beams. In this study, combined with the tensile constitutive relation of fiber reinforced concrete, a weakening coefficient was introduced to describe the stiffness of fiber reinforced concrete after cracking, and a three-dimensional finite element model was established to reflect the tension stiffening effect of fiber reinforced concrete beam reinforced with FRP bars. The simulated load-displacement curves were consistent with the experimental results under different fiber contents and different reinforcement ratios. In addition, the crack patterns obtained by the finite element analysis were in good agreement with the experimental results. With the decrease of the weakening coefficient, the crack propagation slows down, the number of cracks increases and the width decreases under the ultimate load. The study also shows that the weakening coefficient decreases linearly with the increase of the characteristic parameter of fiber content, and the slope was weakly affected by the reinforcement ratio, while the intercept was significantly affected by the reinforcement ratio.

关 键 词：FRP筋 纤维混凝土梁 拉伸刚化 有限元 减弱系数 

分 类 号：TB332[一般工业技术—材料科学与工程]