Reliability Assessment of CFRPStrengthened Deficient Steel SHS Columns

Civil engineers have always been vexed by such numerous problems such as buckling, corrosion, bending, and overloading in damaged steel structures. The present study is aimed to evaluate the effects of the axial loading, axial displacement, stiffness and deficiency location on the length of the deficient steel SHS columns have been evaluated based on a detailed parametric study. Three specimens were tested to failure under axial compression in the lab and simulated using the Finite Element (FE) numerical approach and a total of 100 samples were analyzed by ABAQUS using the MATLAB software to predict the suitable limit state functions and determine the best R2 value through such soft computing techniques as the Artificial Neural Networks, Adaptive NeuroFuzzy Inference System, Response Surface Method, and Gene Expression Programming. Finally, the failure probability and reliability index were obtained by the FORM and Monte Carlo methods on the suggested limit state functions. Results indicated that using CFRP sheets reduced the stress in the damaged location and appropriately prevented or delayed local deformations around the deficient location. So, strengthening steel columns with CFRP can play a significant role in enhancing the rate of the critical load and β, and reducing (Pf ), in deficient columns.