Vibration and Stability Behaviour of Strengthened Thin-Walled Slender RC Columns using CFRP Laminates

Abstract

This paper investigates the vibration and buckling behavior of thin-walled, slender reinforced concrete (RC) columns retrofitted with carbon fiber-reinforced polymer (CFRP) laminates. The study addresses the structural performance of such columns under various partial and concentrated edge loading conditions, which are less explored in existing literature. A finite element code developed in MATLAB is employed to perform a comprehensive parametric analysis. The natural frequencies of the columns are evaluated by incorporating key influencing factors, including load eccentricity, column height, boundary conditions, and ply orientation of CFRP laminates. The impact of applied loads on the dynamic characteristics is also examined. Material properties are carefully computed by accounting for both concrete and embedded reinforcement, ensuring realistic modeling. Furthermore, the buckling behavior of retrofitted columns is studied under varying loading and geometric conditions. Results demonstrate that CFRP retrofitting significantly enhances both stiffness and stability, while load eccentricity and slenderness influence vibration modes and critical loads. This study contributes valuable insights toward the design and analysis of slender RC columns in modern construction systems, especially where retrofitting and performance under complex loading are of concern.