Nonlinear Finite Element Analyses On Stiffness And Deformation Of Concrete Beam Strengthened With FRP

As the reinforced concrete structure entering aging stage or appear cracking, part of the structures can not meet the requirements of normal use, hidding trouble in safety. In addition, the structural cracks will cause people psychological panic. In order to make building structures have a safe use and cut down expense of demolitione, we usually reinforce or transform this kind of building. FRP(Fiber Reinforced Plastic/Polymer, FRP), as one of the most widely applied reinforcement materials in recent years, is used more and more popular in reinforcement or renewal project. FRP includes CFRP(Carbon Fiber Reinforced Polymer/Plastic),GFRP(Glass Fiber Reinforced Polymer/Plastic),AFRP(Aramid Fiber Reinforced Polymer/Plastic) and more other materials. we select CFRP and GFRP to reinforce the test specimen in this paper, researching the deformation and crack distribution of the the reinforced concrete beams. The main contents are as follows:1. According to the test which is on flexural behavior of concrete beams strengthened with FRP, there is a project about the finite element analysis. The first priority is analysis of its constitutive relation and failure criterion of concrete. Then the load model parameters, meshing and setting which based on ANSYS software are discussed to establish finite element simulation model that corresponding to the test of concrete beam.2. According to the numerical model, the experimental beams are analyzed by finite element analysis method. At the same time, the concrete beams with different length of carbon fiber reinforced are simulated. The result of finite element simulation is compared with the test result. This paper introduces an analysis of effect from various parameters(such as FRP length, number of FRP layer, type of fiber, etc.) change on the influence of the reinforced concrete beam.3. The contrast analysis results show that pasting FRP can slow down the progress of the beam in tension zone cracks, while the flexural rigidity and capacity of the beam have been enhanced. But it does not improve linearly, rising slowly gently. We also find that the reinforcement of beam with CFRP is better than that with GFRP, while the former fiber which is several times higher than that of the cost. The concrete beams pasted the same FRP with lower reinforcement ratio have a better reinforcement. The flexural bearing capacity of the beam is improved and at the same time the ductility also will be relatively reduced.4. The analysis results show that the finite element analysis can be used to simulate the process of deformation and cracking of the concrete beams, and its result is consistent with the experiment. For some practical engineering, finite element analysis can do some preview before reinforcement, which has a guiding role in structure strengthening project.