Experimental and numerical investigation of 800 MPa HSS welded T-section column strengthened with CFRP

Abstract

Carbon Fiber Reinforcement Polymer (CFRP) has been widely utilized in repairing and retrofitting engineering. The purpose of this work is to study the buckling behavior of high strength steel (HSS) welded T-section column strengthened with CFRP using experimental and numerical method. The experiment of six specimens of 800 MPa HSS welded T-section column strengthened with CFRP under axial compression is performed. The influences of three main parameters (i.e., the number of CFRP layers, the slenderness of columns, and the width-to-thickness of plates) are observed in this work. All columns fail by the debonding of CFRP layers and the flexural–torsional buckling of specimens. CFRP layer can effectively delay the local buckling of plate or the torsional buckling of specimen. CFRP layer and slenderness has significant influences on the bearing capacity of specimens. The flexural and torsional displacement of columns strengthened with CFRP is much smaller than that of columns without CFRP. A finite element (FE) method for estimating the bearing capacity of HSS welded T-section column strengthened with CFRP is developed using ANSYS software. It is found that the confining effect of CFRP is more effective for stub columns. A more accurate model modified from Cadei et al.’s model for estimating the bearing capacity of 800 MPa HSS welded T-section column strengthened with CFRP under compression is proposed.