Seismic performance of FRP-reinforced concrete-filled thin-walled steel tube considering local buckling

Abstract

The objective of this study is to investigate the seismic performance of fiber-reinforced polymer-reinforced concrete-filled thin-walled steel tube (CFTST). Twelve specimens with different fiber-reinforced polymer types (glass fiber-reinforced polymer and carbon fiber-reinforced polymer) and reinforcing modes were tested under constant axially compressive load and cyclic lateral load. The failure mode and lateral load versus displacement relationship for each specimen were recorded during testing. The strength, ductility, and energy dissipation capacity were analyzed accordingly. Further, a stress–strain relationship and a restoring force model of the fiber-reinforced polymer confining steel tube with local buckling were proposed. A hysteretic model for the fiber-reinforced polymer-reinforced CFTST was developed subsequently. The results indicate that the seismic performance of fiber-reinforced polymer-reinforced CFTST can be effectively improved by optimizing the fiber-reinforced polymer type and corresponding reinforcing scheme. Carbon fiber-reinforced polymer and glass fiber-reinforced polymer are suitable materials for the confinement and bending reinforcement of the column, respectively. The modeling results show the energy imported into the column is mainly dissipated by the thin-walled steel tube. The energy dissipation proportion of the steel tube, concrete core, and longitudinal fiber-reinforced polymer are >80%, 10%–20%, and <8%, respectively. The energy dissipation value of the steel tube can be improved more than 40% after effectively restraining the local buckling.

A State-of-the-Art Review on Axial Compressive Behavior of Concrete-Filled Steel Tubes Incorporating Steel Fiber and GFRP Jacketing

“…In comparison with the specimens with a single circumferential or longitudinal GFRP reinforcement, the ductility was clearly enhanced for the specimens with the GFRP reinforcement (G-B2, G-B4, and G/C-B4). This was primarily due to the outer circumferential FRPs' ability to postpone or even prevent delamination of the GFRP-steel interface while simultaneously confining the steel tube and anchoring the longitudinal GFRP [102].…”

“…The EA capacity of the composite tubes was assessed by Zhu et al [102] using the EA coefficient and equivalent damping coefficient (h e ). For each specimen, the hysteretic loop with summit loading was utilized to compute the EA and h e .…”

“…Zhu et al [102] investigated various failure modes of the specimens and resulted that the longitudinal GFRP specimens had some ductile behavior, because the high glass fibers elongation ratio allowed the specimens to have more deformation. The examined longitudinal CFRP-reinforced specimens, on the other hand, presented a clear brittleness.…”

Numerical studies on the performance of the circular fibre reinforced plastics-concrete filled steel tubes stub column under axial compression

“…20 By bonding the FRP sheets, the steel tube is protected from corrosion, and additional confinement provided by FRP sheets also prevents steel tube from the outward buckling. Therefore, the FRP confined CFST column, or FRP strengthened CFST column 21,22 (hereinafter referred to as FRP-CFST column) has attracted an ever-increasing attentions among the researchers in recent years. According to current literatures, investigations on FRP-CFST column mainly concentrate on its mechanical behaviour under monotonic axial compression [23][24][25][26][27][28][29][30][31][32] .…”

Fibre reinforced polymer for strengthening cylindrical metal shells against elephant’s foot buckling: An elasto-plastic analysis

“…Punitha Kumar and Senthil (2016a, 2016b) investigated the behaviour of an FRP-strengthened slender element of steel circular hollow sections (CHS) under axial loading and observed a significant improvement in ductility, stiffness and loading capacity. The loading capacity and the energy dissipation of concrete-filled steel cylinders under axial and lateral loadings can also be significantly enhanced by confining them with FRP (Lu et al, 2014; Zhu et al, 2018). In this case, the steel tube wall is under internal pressure due to the expansion of concrete which also prevents its inward buckling, while its outward buckling is restrained by the FRP.…”