Shear fatigue life of injected bolted connectors in GFRP sandwich web core panels

Effects of load ratio and aging

Journal Article (2026)
Author(s)

Angeliki Christoforidou (TU Delft - Steel & Composite Structures)

Abishek Baskar (TU Delft - Steel & Composite Structures)

Marko Pavlovic (TU Delft - Steel & Composite Structures)

Research Group
Steel & Composite Structures
DOI related publication
https://doi.org/10.1016/j.tws.2026.114901 Final published version
More Info
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Publication Year
2026
Language
English
Research Group
Steel & Composite Structures
Journal title
Thin-Walled Structures
Volume number
226
Article number
114901
Downloads counter
10
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Abstract

The durability of bridge connections is critical for the long-term performance of bridge systems with GFRP composite decks. This study investigates the shear fatigue behaviour of injected Steel Reinforced Resin (iSRR) connectors embedded in FRP composite decks, through a series of fatigue tests performed under different load ratios and exposure conditions. Twenty-four connectors are examined: twelve unaged reference specimens, eight specimens tested under varying R ratios, two connectors with deck parts submerged in water and two subjected to outdoor aging, both for a duration of one year. The results show that, despite the composite nature of the connector, the load ratio and mean load level have minimal influence on fatigue life. Instead, fatigue performance in the high-cycle regime is governed primarily by the applied load range. A unified F-N curve including all R ratios was developed, demonstrating the consistency of this trend and enabling fatigue-life prediction across different loading conditions. Environmental exposure led to measurable stiffness degradation but did not significantly alter fatigue life. These findings highlight the robustness of the iSRR connector and support its application in durable GFRP-steel hybrid bridge systems.