Experiment and theoretical analysis of carbon fiber reinforced polymer strengthened square steel tube under eccentric load

Abstract

Carbon fiber reinforced polymer (CFRP) has many advantages, such as light weight, high strength, and excellent corrosion resistance. In this paper, the experimental research of the square steel tube reinforced by carbon fiber reinforced polymer was performed, and its ultimate bearing capacity formula was derived. The tests were based on the previous results of our research group. Six sets of the test are performed by altering two-layer-CFRP and the eccentricity. The test results demonstrated that CFRP improved the ultimate bearing capacity of square steel tubes. As the number of layers of CFRP increased, the growth rate of bearing capacity gradually declined, and reinforcement of CFRP on specimens of large eccentricity was significantly effective than that of small eccentricity one. After longitudinal CFRP was stuck, a circumferential layer of CFRP in the middle of the square steel tube can improve the reinforcement effect. This paper referred to the existing codes and took the idea of area substitution to derive the ultimate bearing capacity formula of the steel tube reinforced by CFRP. The calculated values of the formula were compared with those of the experiment, and the difference is within the range, which proves the rationality of the derived formula.