A Finite Element Analysis On Reinforced Concrete T-beams Strengthened With CFRP

The need for upgrading, strengthening, retrofitting, and rehabilitating existing structures, or damaged ones, is one of the most important problems that structural engineers face. Strengthening concrete structures with Fiber Reinforced Plastic (FRP) is a new structural repair method in recent years. This method has been found to be economical and efficient to apply, because of its resistance to electrochemical erosion, low manpower demand for application and minimal changes in geometrical dimensions of member.To develop a more thorough understanding of the bending behavior of reinforced concrete beams, the study on nonlinear finite element analysis is very imperial. Based on the experiments of the bending behavior of RC simply supported beams strengthened with CFRP, nonlinear finite element analysis is presented on the basic mechanics performances of RC T-beams strengthened with CFRP in the ADINA software environment.First, the paper sets up finite element models of 4-point bending RC beams strengthened with CFRP sheet. Not only material nonlinear of concrete and steel bar but also bond styles of longitudinal steel and CFRP are taken into account. In this paper, spread-finite element model is adopted. Different element types are used in the model. Longitudinal steel is modeled using 2-node truss element. Concrete is modeled using 8-node three- dimensional solid element with the performance of crack and crush and CFRP sheet is modeled using three-dimensional element. At the same time, it is assumed that the bonding between steel bar, CFRP sheet and concrete is in good condition. Under concentrated load, using finite element method, deflection of beams at center of span, and load-stress, load-strain of steel bar and CFRP sheet are analyzed for RC simply supported beams strengthened with different types of CFRP sheet. At one time, we also calculate deflection of beams at center of span under line load. If the basic assumptions are satisfied, the results show that the results obtained from the test, which compared with those of finite element method analysis, indicate that they are in a good agreement. It well shows rationality and applied value of the finite element model. Next, the influences of CFRP area, reinforcing steel ratio and compressive strength of concrete on the reinforcing effect are analyzed.At last, the paper summarizes the finite element method analysis results of the flexural behavior of RC T-beam strengthened with CFRP sheet. Some expectation and assumption about the next research are brought forward.