Numerical analysis on mechanical properties and failure mode of GFRP-concrete composite beam

Based on the experiments of the GFRP-concrete composite beam, the mechanical property and failure mode of GFRP concrete composite beams are numerically analyzed. Taking into account the anisotropy and stiffness degradation of GFRP, the Hashin criteria is implemented by the VUMAT Model in ABAQUS. The interfacial element by using the bilinear cohesive model is introduced to simulate the bond slip behavior between GFRP flange and concrete slab. The validity of the numerical model is verified by comparing with the results of experimental tests of full GFRP I-profile and GFRP-concrete composite beam. The effects of the strength, thickness, width of concrete slab, and the height of GFRP web on the mechanic performance and failure mode of the composite beam are studied. The results show that the material softening of GFRP and interfacial bond-slip have important influence on the mechanical properties of the composite beam. The increasing strength and thickness of concrete slab would improve the bearing capacity of the composite beam, but excessive compression strength of concrete would lead to longitudinal shear failure of the slab. In addition, the web height of the GFRP profile has a significant effect on the cross-section stress and strain distribution of the composite beam.