复合受力模式下FRP片材-混凝土界面的受力行为及承载力预测  

Bond behavior and capacity prediction of FRP laminate-to-concrete interface under mixed-mode loading

作　　者：施嘉伟 徐冰雷 Shi Jiawei;Xu Binglei(College of Civil and Transportation Engineering, Hohai University, Nanjing 210098, China)

机构地区：[1]河海大学土木与交通学院,南京210098

出　　处：《东南大学学报（自然科学版）》2022年第3期489-496,共8页Journal of Southeast University：Natural Science Edition

基　　金：国家自然科学基金资助项目(51508157);河海大学中央高校基本科研业务费资助项目(B200202080).

摘　　要：针对纤维增强树脂复合材料(FRP)片材外贴加固混凝土构件中存在的界面复合受力剥离问题,开展了复合受力模式下FRP片材-混凝土界面的受力行为研究.以带初始加载角的FRP片材-混凝土双面剪切试件为研究对象,采用幂法准则作为界面的起始损伤与失效准则,建立有限元分析模型.在试验验证的基础上开展了参数分析,发现初始加载角与FRP黏结长度对复合受力模式下的界面受力性能影响相对较大.然后,基于数值模拟结果对现有FRP片材混凝土界面承载力模型进行修正,得到了能够考虑复合受力模式的界面承载力预测模型.最后,建立了考虑界面复合受力模式的试验数据库以验证模型的预测精度,发现修正后的界面承载力预测模型能够较好地考虑复合受力模式的影响,预测结果的变异系数由31.3%降低至17.4%,预测精度显著提高.该研究为FRP片材加固混凝土构件中的界面复合受力问题分析及承载力计算提供了参考.To solve the problem of mixed-mode interfacial debonding in concrete members strengthened with externally-bonded fiber reinforced polymer(FRP)laminate,the bond behavior of FRP laminate-to-concrete interface under mixed-mode loading was studied.First,the double-lap shear specimens with initial load angle were numerically modeled.The power law was employed as interfacial initial damage law and failure law in the numerical model.After validation of the numerical model by test results,a series of parameter analyses were carried out.It was found that the initial load angle and the FRP bond length had more significant influence on the bond behavior of FRP laminate-to-concrete interface under mixed-mode loading.Then,a FRP laminate-to-concrete bond capacity model considering mixed-mode loading was proposed by the modification of an existing model based on the numerical results.Finally,a test database considering interfacial mixed-mode loading was established to validate the model.It was found that the modified model could predict the bond capacity of FRP laminate-to-concrete interface more precisely than the original model.The coefficient of variation of the prediction results decreased from 31.3%to 17.4%after modification,showing a significant increase in prediction accuracy.This study can provide a reference for the bond behavior analysis under mixed-mode loading and load capacity prediction of FRP strengthened concrete members.

关 键 词：FRP加固 混凝土 界面黏结 复合受力模式 界面承载力 

分 类 号：TB332[一般工业技术—材料科学与工程]