Hu Han, Lopes Sergio M R, Lopes Adelino V, Lou Tiejiong
School of Civil Engineering and Architecture, Wuhan University of Technology, Wuhan 430070, China.
CEMMPRE, Department of Civil Engineering, University of Coimbra, 3030-788 Coimbra, Portugal.
Materials (Basel). 2022 Sep 1;15(17):6052. doi: 10.3390/ma15176052.
Reinforced concrete (RC) frame beams are subject to axial restriction at the ends, which plays an important role in the nonlinear behavior of these beams. This paper presents a numerical and theoretical investigation into the flexural behavior of RC beams axially restricted with external steel or fiber reinforced polymer (FRP) reinforcement. A numerical procedure for RC beams axially restricted with external reinforcement has been developed and it is verified against available experimental results. A numerical parametric study is then performed on axially restricted RC beams, focusing on the effect of type, area, and depth of external reinforcement. The results show that axial restriction increases the post-cracking stiffness and ultimate load-carrying capacity but reduces the flexural ductility. The ultimate stress in external reinforcement is substantially impacted by reinforcement type, area, and depth. A simplified model is developed to predict the ultimate load of RC beams axially restricted with external steel/FRP reinforcement. The predictions of the proposed simplified model agree favorably with the numerical results. The correlation coefficient for the ultimate load is 0.984, and the mean difference is -2.11% with a standard deviation of 3.62%.
钢筋混凝土（RC）框架梁在端部受到轴向约束，这对这些梁的非线性行为起着重要作用。本文对采用外部钢或纤维增强聚合物（FRP）加固的轴向约束RC梁的弯曲行为进行了数值和理论研究。开发了一种用于外部加固轴向约束RC梁的数值程序，并根据现有的实验结果进行了验证。然后对轴向约束RC梁进行了数值参数研究，重点关注外部加固的类型、面积和深度的影响。结果表明，轴向约束增加了开裂后刚度和极限承载能力，但降低了弯曲延性。外部加固中的极限应力受到加固类型、面积和深度的显著影响。开发了一个简化模型来预测采用外部钢/FRP加固的轴向约束RC梁的极限荷载。所提出的简化模型的预测结果与数值结果吻合良好。极限荷载的相关系数为0.984，平均差异为-2.11%，标准差为3.62%。
