Numerical simulation on behavior of damaged composite girders repaired using CFRP sheets

Abstract

This study investigated the behavior of corrosion damage-repaired steel–concrete composite girders with CFRP sheets using finite element (FE) analysis. The corrosion-induced damage in the girder was simulated by removing a cross-sectional area of 1480 mm × 4.5 mm from the top surface of the bottom steel flange at the midspan. Afterward, six-layer CFRP sheets were bonded to the underside of the lower flange with epoxy resin as a repair method. A reference model without damage was also considered. FE models of these specimens were established, and a nonlinear FE analysis was conducted. The FE models were validated using experimental results and then used to perform a parametric study considering the limited number of parameters: number of layers and elastic modulus of CFRP sheets. Comparison between experimental and numerical results revealed that the FE simulation could accurately capture the failure orders and predict the comprehensive behavior of CFRP-repaired steel concrete composite girders. Furthermore, an equation was proposed to predict the carrying load-carrying capacity of the CFRP-repaired steel-concrete composite girder. The proposed equation was used to calculate the targeted load-carrying capacity and showed closer values to the numerical results. However, more parameters are required to include in the equation for the rational design method.