纤维增强复材-钢界面有效黏结长度模型对比研究

COMPARATIVE RESEARCH ON EFFECTIVE BOND LENGTH MODELS FOR FRP-TO-STEEL INTERFACES

采用外贴纤维增强复合材料(FRP)加固修复钢结构近年来得到广泛应用,外贴FRP与钢界面之间存在有效黏结长度,当黏结长度大于该长度时,界面黏结强度不再随长度增加。因此,有效黏结长度是FRP加固修复钢结构设计时确定界面黏结长度的重要参数。通过对已有FRP-钢界面有效黏结长度模型的总结,建立了包括31组有效黏结长度试验结果的数据库,对已有模型预测有效黏结长度的准确性和设计黏结长度的适用性进行了对比评估。与试验结果对比表明:Xia-Teng模型对有效黏结长度试验值的预测最准确,但已有的有效黏结长度模型预测结果均不够安全,不能直接用于FRP-钢界面黏结长度设计。为此,基于Xia-Teng模型,分析建议了FRP-钢界面黏结长度设计方法。该建议方法保守且合理,可用于FRP加固修复钢结构设计。

Recently, the use of externally bonded fiber reinforced polymer (FRP) for strengthening steel structures has attracted significant attention. For an externally bonded FRP-to-steel interface, there is an effective bond length, beyond which the bond strength of the interface does not increase. Thus, the effective bond length is important for the design of the bond length. The paper collected existing effective bond length models and established a database containing the test results of 31 bonded joints. A comparative research on the accuracy of existing models for predicting the test results and the applicability of existing models for design the bond lengths was presented. Compared with test data, the results showed that Xia-Teng's model was of the highest accuracy for predicting the effective bond lengths. However, the predictions by existing effective bond length models were non-conservative and could not be directly used for the design of the bond lengths between FRP and steel. Based on Xia-Teng s models, an analysis was conducted and a design method was proposed for the bond lengths of FRP-to-steel interfaces. The proposed method is conservative and reasonable and can be applied for the design of the bond lengths of FRP-strengthened steel structures.