界面缺陷对CFRP加固钢筋混凝土梁抗弯性能的影响研究

Study on the effect of interface defects on the flexural behavior of RC beams strengthened with CFRP

为研究界面缺陷对CFRP加固钢筋混凝土梁抗弯性能的影响,制作了3根钢筋混凝土梁对比试件,并进行了四点弯曲试验。同时,采用ABAQUS分析软件建立了非线性有限元模型,并进行了数值模拟分析。结果表明:当存在多个不连续缺陷时,试件上的CFRP提前发生剥离,剥离荷载下降了20.77%,导致试件的破坏模式发生改变,虽然极限荷载仅降低2.46%,但挠度降幅高达15.37%,延性下降显著;界面缺陷附近易产生应力集中,促使多裂缝均衡发展,导致裂缝间距减小;界面缺陷影响CFRP剥离起始发生位置,更易引起CFRP沿试件宽度方向贯穿剥离。

In order to study the interface defects on the flexural behavior of RC beams strengthened with CFRP,3 comparative specimens were made and four-point bending tests were conducted.At the same time,a nonlinear finite element model was established by using ABAQUS software,and the numerical analysis was conducted.The results show that when there are multiple interface defects in the specimens,the CFRP debonding occurs in advance and the debonding load decreases by 20.77%,which leads to a change in the failure mode of the specimens.Although the ultimate load decreases by only 2.46%,the deflection decreases by 15.37%and the ductility decreases significantly.Stress concentration is easy to occur near the interface defects,forming the balanced development of multiple cracks,resulting in the reduction of crack spacing.The interface defect affects the initial location of CFRP stripping,which is more likely to cause CFRP stripping along the width direction to form penetration.