strengthening of deficient steel sections using cfrp composite under combined loading

Recently, strengthening of steel sections using carbon fiber reinforced polymer (cfrp) has come to the attention of many researchers. for various reasons, such structures may be placed under combined loads. the deficiency in steel members may be due to errors caused by construction, fatigue cracking, and other reasons. this study investigated the behavior of deficient square hollow section (shs) steel members strengthened by cfrp sheets under two types of the combined loads. to study the effect of cfrp strengthening on the structural behavior of the deficient steel members, 17 specimens, 12 of which were strengthened using cfrp sheets, were analyzed. to analyze the steel members, three dimensional (3d) modeling and nonlinear static analysis methods were applied, using ansys software. the results showed that cfrp strengthening had an impact on raising the ultimate capacity of deficient steel members and could recover the strength lost due to deficiency, and the impact of cfrp strengthening on rising and recovering the ultimate capacity of the steel members under loading scenario 2 was more than the steel members under scenario 1.