Document Type : Research Article
Associate Professor, Department of Civil Engineering, Kerman-branch, Islamic Azad University, Kerman, Iran
Assistant Professor, Department of Civil Engineering, Zahedan Branch, Islamic Azad University, Zahedan, Iran
Department of Civil Engineering, Sirjan Branch, Islamic Azad University, Sirjan, Iran
Steel structures are damaged for a variety of reasons including accidental loads, corrosion and reduced strength which need to be repaired and improved. In this investigation, local corrosion was applied to the steel circular columns and the effects of Carbon Fiber Reinforced Polymer (CFRP) for strengthening has been studied. 19 specimens of steel Circular Hollow Section (CHS) column with the same height and damage dimensions under compressive load were analyzed by ABAQUS software which six cases of them were performed experimentally. In laboratory cases, progressive corrosion was used to create damage on the specimens. In order to improve the accuracy of the analysis, a combined method was used to study the post-buckling of the plastic zone. For this purpose, the specimens were first subjected to elastic buckling analysis and then Riks non-linear analysis with global and local imperfections was conducted. The results showed that the corrosion reduces the bearing capacity and rigidity of the steel columns and complete destruction of the corroded area reduced the load bearing capacity by 40% for the column with corrosion at the middle and by 21% for the damage close to the base, which shows the former is more critical. Strengthening of columns retrofitted with carbon fibers restored ultimate load reduction by 33% and have a positive effect on controlling fractures and reducing stresses at the damaged area.