Title: Evaluation of Hysteretic Energy and Damping Capacity of GFRP-RC Columns Under Cyclic Loading

Author(s): Yasser M. Selmy, Amr E. Abdallah, and Ehab F. El-Salakawy

Publication: Symposium Paper

Volume: 360

Issue:

Appears on pages(s): 628-647

Keywords: GFRP reinforcement, hysteretic response, seismic performance, energy dissipation, displacement ductility, viscous damping.

DOI: 10.14359/51740653

Date: 3/1/2024

Abstract:
The seismic performance of reinforced concrete (RC) structures relies on their ability to dissipate earthquake-induced energy through hysteric behavior. Ductility, energy dissipation, and viscous damping are commonly used as performance indicators for steel-RC seismic force-resisting systems (SFRSs). However, while several previous studies have proposed energy-based indices to assess energy dissipation and damping of steel-RC SFRSs, there is a lack of research on fiber-reinforced polymer (FRP)-RC structures. This study examines the applicability of the existing energy dissipation and damping models developed for steel-RC columns to glass FRP (GFRP)-RC ones, where the relationships between energy indices and equivalent viscous damping versus displacement ductility were analyzed for GFRP-RC circular columns from the literature. In addition, prediction models were derived to estimate energy dissipation, viscous damping, and stiffness degradation of such types of columns. It was concluded that similar lower limit values for energy-based ductility parameters of steel-RC columns can be applied to GFRP-RC circular columns, whereas the minimum value and analytical models for the equivalent viscous damping ratio developed for steel-RC columns are not applicable. The derived models for energy indices, viscous damping, and stiffness degradation had an R2 factor of up to 0.99, 0.7, and 0.83, respectively. These findings contribute to the development of seismic design provisions for GFRP-RC structures, addressing the limitations in current codes and standards.