Title:
Numerical Response of Concrete‑Filled Steel Tubular (CFST) Columns Externally Strengthened with FRP Composites Subjected to Cyclic Loading
Author(s):
Walid Mansour, Bothaina Osama, Weiwen Li, Peng Wang and Md. Habibur Rahman Sobuz
Publication:
IJCSM
Volume:
19
Issue:
Appears on pages(s):
Keywords:
Concrete-filled steel tubular (CFST) columns, Cyclic loading, Finite element model, Fiber-reinforced polymers (FRPs), Absorbed energy, Stiffness, Viscous damping
DOI:
10.1186/s40069-024-00716-6
Date:
3/31/2025
Abstract:
The ultimate load-carrying capacity of concrete-filled steel tubular (CFST) columns exposed to monotonic loadings
can be greatly increased by strengthening those columns, and the occurrence of the steel tube’s outward buckling
can be postponed. The current research aims to study the possibility of improving the structural characteristics
of CFST columns exposed to cyclic loadings in terms of lateral load capacity and absorbed energy by strengthening
them with different patterns of fiber-reinforced polymer (FRP) sheets. The ABAQUS software was used to create
a three-dimensional (3D) non-linear finite element model (FEM) to simulate the behavior of FRP-strengthened
CFST columns exposed to monotonic and cyclic loadings. After ascertaining the accuracy of the proposed model’s
results in successfully predicting failure patterns and lateral loads compared to the experimental results of tested
specimens available in the literature, the model was used to create a parametric study. The parametric study focused
on the impacts of the thickness, location, and length of the strengthening sheets on the failure pattern, lateral loadcarrying
capacity, stiffness, cumulative energy, absorbed energy, and viscous damping factor of the CFST columns
exposed to cyclic loadings. The results revealed that the un-strengthened specimen displayed a maximum lateral load
of 185 kN and a viscous damping factor of 45.2% at a lateral drift of 5.7%. On the other hand, strengthening the CFST
column using five layers of FRP sheets exhibited the highest lateral load of all investigated columns (50% more
than the un-strengthened specimen). Additionally, at a lateral drift of 5.7%, the decrease in viscous damping factor
of CFST specimens due to strengthening using 1, 2, 3, 4, and 5 layers of FRP sheets with respect to the control specimen
was 7.9%, 14.9%, 20.8%, 27.7%, and 30.3%, respectively.