Behavior of RC beams strengthened with CFRP plates using the finite element modeling

ABSTRACT

During the last decade, strengthening of RC structures with CFRP (carbon fiber reinforced polymer) composite has become very popular. In the present work, numerical analysis was performed using the ANSYS finite element software to predict the performance of RC beams strengthened with CFRP plates. The concrete was modeled as 3-dimentional solid elements having nonlinear properties. The reinforcing steel was modeled as linkage elements with elastic-plastic behavior. The CFRP was modeled as plane shell elements attached to the concrete surface. The efficiency of the present model was measured by comparing its results with the available experimental results; good agreement was found between the numerical and experimental studies. The influences of CFRP plate length factor, concrete strength and steel reinforcement area on the performance of RC strengthened beams were investigated. It has been shown that the use of CFRP strengthening can significantly increase the ultimate load carrying capacity as well as the stiffness of RC beams. The major effect was found at a plate length factor of 0.8. The effect of CFRP strengthening on the behavior of beams with low area of steel reinforcement was more pronounced than that of beams with high area of steel reinforcement.