Nonlinear Finite Element Analyses On Bending Capacity Of Reinforced Concrete Beam Strengthened With CFRP

The reinforcement of steel concrete structures attracts the attention of engineers as one of the hot spots. Carbon fiber, with its high-strength, lightweight, and corrosion resistance, gradually replaces the traditional materials and is being widely used in bending and shear reinforcement project. At present, the analysis on strengthening effect in carbon fiber reinforcement is still not perfect and does not form a complete theoretical system. So an in-depth analysis in this area has a great significance.In this paper, the non-linear finite element analysis was done by ANSYS. A simply supported steel concrete beam was considered because it has testing data. The corresponding finite element model was built. Simulations were done to the original model and its carbon fiber reinforced beams by different layers. Based on the existing experimental data, the effect of some factors ,such as Harding model, crushing switch, loading form, load-step, shear transferring coefficient in opening cracks, grid density etc, to ANSYS results were analyzed. Accordingly a series of parameter settings and value domain were determined for reasonable simulation. Finally, the rationality examination of the built model was done through the comparison between the simulation results and experimental data.Based on the above results, 10 finite element models were generated to do the impact analysis of certain factors such as the location, length, direction and the number of carbon fiber layers; the longitudinal ratio of reinforcement, the height of cross-section, the ratio of shear span to depth, the concrete intensity level of the beam; the load form etc., on the reinforcement of steel concrete rectangular simple beam. Another 4 finite element models were created for the rectangular cantilever beams to analyze the effect of the location, length, number of carbon fiber layers, and the load form on their reinforcement. As results, the effect of the above varieties on the bearing capacity of reinforced beam was obtained. Furthermore, the optimized values of some varieties were determined. In addition, the comparisons of bearing capacity, stiffness and stress distribution of the longitudinal bars before and after reinforcement were done. By studying their changing reasons and development laws, further performance of these carbon fiber enhanced steel concrete beams were revealed.