Abstract:

It has been confirmed that an externally-bonded carbon fibre-reinforced polymer （CFRP） plate can effectively improve the strength and stiffness of steel-concrete composite beams. In this paper, the nonlinear finite element （FE） method was used to calculate the ultimate bearing capacity and stiffness of the simply-supported CFRP strengthened composite beams, and the effects of adhesive and shear studs were also discussed. Then, the nonlinear FE results were compared with the theoretical and experimental ones. Analytical results indicate that （ 1 ） both the stress-strain curve and the longitudinal strain of CFRP plate obtained by nonlinear FE analysis are in good agreement with the experimental ones; （2） the nonlinear FE model considering the joint is more accurate than the one not considering the joint ; （3） The effect of CFRP is not significantly displayed until the steel beam yields ; and （4） as compared with the results obtained by other analytical methods, the results obtained by the nonlinear FE model considering the joint are more close to the experimental ones, with an error of less than 2.5%.

Key words: carbon fibre-reinforced polymer, steel-concrete composite beam, ultimate bearing capacity, nonlinear finite element