华南理工大学学报(自然科学版) ›› 2022, Vol. 50 ›› Issue (11): 95-106.doi: 10.12141/j.issn.1000-565X.220105

所属专题: 2022年土木建筑工程

• 土木建筑工程 • 上一篇    下一篇

FRP胶栓混接节点疲劳性能试验研究

王进潇李思达1 程斌闫兴非2 张凯龙2   

  1. 1.上海交通大学 船舶海洋与建筑工程学院,上海 200240
    2.上海市城市建设设计研究总院(集团) 有限公司,上海 200125
  • 收稿日期:2022-03-03 出版日期:2022-11-25 发布日期:2022-07-29
  • 通信作者: 程斌(1979-),男,教授,主要从事钢结构、浮桥研究。 E-mail:cheng_bin@sjtu.edu.cn
  • 作者简介:王进潇(1993-),男,博士生,主要从事复合材料桥梁研究.Email:youz-wjx@sjtu.edu.cn.
  • 基金资助:
    国家自然科学基金资助项目(51978400)

Experimental Study on Fatigue Behavior of Adhesive & Bolted Hybrid FRP Joints

WANG Jinxiao1 LI Sida1 CHENG Bin1 YAN Xingfei2 ZHANG Kailong2   

  1. 1.School of Naval Architecture, Ocean & Civil Engineering, Shanghai Jiao Tong University, Shanghai 200240, China
    2.Shanghai Urban Construction Design and Research Institute(Group)Co. , Ltd. , Shanghai 200125, China
  • Received:2022-03-03 Online:2022-11-25 Published:2022-07-29
  • Contact: 程斌(1979-),男,教授,主要从事钢结构、浮桥研究。 E-mail:cheng_bin@sjtu.edu.cn
  • About author:王进潇(1993-),男,博士生,主要从事复合材料桥梁研究.Email:youz-wjx@sjtu.edu.cn.
  • Supported by:
    the National Natural Science Foundation of China(51978400)

摘要:

FRP胶栓混接节点兼具胶接节点和栓接节点的优点,静力性能优良,但疲劳破坏机理尚不明确;为了深入研究FRP胶栓混接节点在多种工况下的疲劳性能,文中设计制作了单搭接FRP胶栓混接节点试件。首先进行轴向拉伸及四边剪切作用下的静载试验,得到了相应的破坏模态和极限承载力;随后开展两种工况下的高周疲劳荷载试验,采用声发射技术测得了胶层的疲劳损伤发展过程,得到了试件的疲劳破坏模式、特征疲劳寿命以及刚度退化规律,并提出了疲劳寿命预测方法建议。结果表明:FRP胶栓混接节点的抗疲劳性能主要由栓接控制,其疲劳破坏过程可分为胶层累积损伤、胶层破坏、FRP累积损伤、FRP破坏4个阶段,其中胶层破坏阶段和FRP破坏阶段的声发射特征参数发生显著变化,可作为识别破坏发生的依据;当螺栓数量较少时两种工况下的试件均发生螺帽挤入FRP板的破坏,当螺栓数量较多时拉伸试件以FRP板孔边拉剪破坏为主,剪切试件以FRP板整体剪切破坏为主;螺栓数量增加能够显著提升拉伸试件的特征疲劳寿命,并有效抑制疲劳破坏过程中的刚度下降速度,但剪切试件的疲劳性能对螺栓数量不敏感;基于试验数据拟合得到的不同工况下的S-N曲线公式可为FRP胶栓混接节点疲劳寿命计算提供参考,有助于此类节点在桥梁等主要承受反复荷载作用结构中的应用。

关键词: FRP节点, 胶栓混接, 疲劳性能, 轴向拉伸试验, 疲劳破坏模式, 特征疲劳寿命, 声发射技术

Abstract:

FRP adhesive & bolted hybrid joint has the combined advantages of adhesive joints and bolted joints, which behave enhanced static performance, but its fatigue failure mechanism still needs to be studied. In order to study the fatigue performance of hybrid FRP joints under various working conditions, this study designed and manufactured single-lap hybrid FRP joints specimens. Firstly, the static load tests under axial tension loads and four side shear loads were carried out, and the corresponding failure modes and ultimate bearing capacity were obtained. Then, high cycle fatigue tests under two working conditions were carried out, and the damage process of the adhesive layer was measured by acoustic emission (AE) technology. The fatigue failure mode, characteristic fatigue life and stiffness degradation of the specimen were obtained, and the fatigue life prediction method was proposed. The results indicate that the anti- -fatigue performance of hybrid FRP joints is mainly controlled by bolted-connection, and its fatigue failure process can be divided into four stages: adhesive layer cumulative damage, adhesive layer failure, FRP cumulative damage, and FRP failure. Among them, the AE characteristic parameters of adhesive layer failure stage and FRP failure stage change significantly, and this can be used as the basis for identifying the failure occurrence. When the number of bolts is small, two working condition show the similar failure mode of the nut squeezing into the FRP plate. When the number of bolts is large, for tensile specimens, the tensile-shear failure mainly occurs at the hole of the FRP plate; for shear specimens, the failure mode is overall shear failure of FRP plate. The increase of the number of bolts can significantly improve the characteristic fatigue life of tensile specimens, and effectively inhibit the stiffness degradation during fatigue loads, but the improvement of fatigue performance of shear specimens is not obvious with the increasing number of bolts. The S-N curve of two working conditions obtained based on the test data can provide a reference for the fatigue life calculation of hybrid FRP joints, and help the application of such joints in bridges and other structures that mainly bear repeated loads.

Key words: FRP joint, adhesive &, bolted hybrid connection, fatigue behavior, axial tensile test, fatigue failure mode, characteristic fatigue life, acoustic emission

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