Numerical Simulation Analysis of RC Beams Strengthened with CFRP Using Viscoelasticity Constitutive

In order to investigate the mechanical behavior influence of the adhesive viscoelastic on reiforced concrete beams strengthened with the carbon fiber reinforced polymer, the Burger model was used to describe the stress-strain-time relation for the adhesive. The relaxation shear modulus with Prony series forms of Burger model was derived by the mathematical method of Laplace transform and inverse Laplace transform. The finite element software ABAQUS was used to simulate RC beams strengthened with the CFRP. The influence of the adhesive viscoelastic on the stresses of the adhesive, the axial force of the CFRP, the moment of RC beams and the deflection of the reinforced beam were analyzed. The results show that the adhesive viscoelastic affect the mechanical behavior of the reinforced beam to a certain degree. With the increasing of the loading time, the shear stresses and normal stresses peak value of the adhesive decrease, the axial force of the CFRP decrease, the bending moment of the RC beam increase and the deflection of the reinforced beam increase. When the adhesive layer thickness is 0.2 mm, and the reinforced beam has been loaded for 30 d. The peak shear stress decreases by 40.1%, the normal peak stress decreases by 33.0%, the deflection of the reinforced beam increase by 3.7 ‰. On the cross section 20 mm away from the end of the CFRP, the CFRP axial force decreases by 15.8% and the bending moment of the RC beam increases by 17.4%.