Nonlinear Finite Element Analysis Of Reinforced Concrete Flexural Members Strengthened By Side-bonded Carbon Fibers

The large-scale new construction mode in the engineering field has seen a significant slowing down trend,and the reinforcement and repair can be based on the original building,and will reconstruct a series of problems caused by the aging of the structure and the change of the use function of the building.As a new and high-tech building reinforcement method,carbon fiber reinforcement technology has been continuously applied in engineering practice.The application of carbon fiber cloth on the surface of concrete can improve the performance of reinforced concrete structures.At present,there are many researches on reinforced concrete bent members reinforced with carbon fiber at the bottom,and it is not suitable for carbon fiber materials when pipes,power lines,etc.,are closely considered at the bottom of the beam,or when there are walls and other obstacles under the beams.Bottom stickers,so this paper studies the feasibility of this reinforcement method by pasting carbon fiber cloth on both sides of reinforced concrete beams.In this paper,based on the experimental data of existing CFRP-reinforced RC beams,the mechanical properties of carbon fiber reinforced visco-reinforced beams are studied through theoretical calculations combined with finite element numerical analysis methods.The calculation formula of the beam's normal section bending capacity and the correctness of the method are verified based on a concrete example.On this basis,the finite element software ANSYS is used to establish the separated finite element of the CFRP reinforced concrete beam.In the model,nonlinear finite element analysis was performed on different types of reinforced beams,and the analysis results were compared with the experimental results to verify the rationality of the finite element model.The main conclusions are as follows:(1)According to the specifications and test data,the calculation formula of the flexural capacity of the cross-section of the carbon fiber side-adhesion strengthened beam under three failure modes was established.Through comparative analysis,the simplified calculation value is in good agreement with the experimental value,which proves that it can meet the project.Reinforcement design requirements;(2)Side-adhering carbon fiber can increase the ultimate bearing capacity of the flexural member,enhance the rigidity and ductility of the member,and improve the mechanical properties of the reinforced concrete flexural member,especially the restraint effect on the crack,and the carbon fiber on the side makes the crack develop.The direction is perpendicular to the carbon fiber cloth,so that it has a good barrier effect on the cracks,making the crack development in the direction of small and dense,no longer produce large cracks,improving the overall stability of the bending member;(3)With the increase of the number of carbon fiber layers,the ultimate bearing capacity of the beam is also increasing,but the reinforcement efficiency will be reduced,and the number of carbon fiber adhesive layers is generally not more than three layers;under the same amount of carbon fiber,the glued position is closer to the beam.In the body's tension zone,the better the reinforcement effect,the side-adhesion height of the carbon fiber is generally not more than 1/3 of the beam height.