@article{WANG2022, 
author = {Jinxiao WANG and Sida LI and Bin CHENG and Xingfei YAN and Kailong ZHANG},
title = {Experimental Study on Fatigue Behavior of Adhesive & Bolted Hybrid FRP Joints},
year = {2022},
journal = {Journal of South China University of Technology (Natural Science Edition)},
volume = {50},
number = {11},
pages = {95-106},
keywords = {FRP joint, adhesive & bolted hybrid connection, fatigue behavior, axial tensile test, fatigue failure mode, characteristic fatigue life, acoustic emission},
url = {https://www.sciopen.com/article/10.12141/j.issn.1000-565X.220105},
doi = {10.12141/j.issn.1000-565X.220105},
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.}
}