Fine Finite Element Analysis On H-Shaped Steel Beam Strengthened With CFRP

Carbon fiber reinforced polymer (CFRP) has been widely used in reinforcement engineering because it has many advantageous characters, such as low weight, high strength, anti-corrosion and simple construction. The existing reinforced steel structures can be strengthened by adhering CFRP on the steel beam surface to improve their mechanical performances. Many researchers have done lots of work on CFRP. But they only partially focused on test research work and corresponding theory analysis. The fine finite element work in system on CFRP strengthening steel beam is absent. The extended finite element method (XFEM) can be used on the simulation of the non-linear and full-size analysis on the behavior of strengthened beams. This method can be used in nonlinear analysis and especially failure analysis, without re-meshing when dealing with the crack propagation problems. It has advantages in large deformation analysis, fracture propagation, friction contact problems, and also can save lots of human resource and material in model test. This kind of analysis method can provide theory basis for strengthening design and construction.In this paper the CFRP-glue-beam extended finite element model has proposed based on XFEM in ABAQUS. The XFEM model of CFRP strengthened steel beam was verified through test and comparing analysis. Experiments of H-shaped beams bonded with CFRP are used for accuracy verification. Based on this model, the total analysis and study on single steel girder and reinforced steel girder strengthened with CFRP were done. The influence factors on strengthening effectiveness were discussed. The whole work in this paper is listed as follow: 1We made a summary on the previous theory and experiment research by investigation of most corresponding papers, presented the research target and main contents of this paper. The adhesive construction and all the formal cohesive strength models were summarized.2Combined with fracture mechanics, the author introduced the basic theory of XFEM and virtual node method. In this paper the detailed implementation in ABAQUS were also presented by some analysis examples.3The CFRP-glue-beam finite element model was proposed in the paper based on XFEM in ABAQUS. Experiments of H-shaped beams bonded with CFRP are used for accuracy verification, which prove the modeling method is available and the analysis results are reliable.4Based on the CFRP-glue-beam model, the author has done much work on the system analysis and study on single steel girder without crack and reinforced steel girder with crack, and strengthened with CFRP under the different parameters. Parameter analysis on the XFEM model was done in ABAQUS. The author also compared the influences by different glue parameters or different damage parameters of strengthened beam, interfacial normal and shear stress in glue layer. At last we presented some useful conclusions on plasticity design of the strengthened beam in ultimate state.