Research On Flexural Test And Finite Element Numerical Simulation Of Prestressed CFRP Reinforced Beams

In recent years,with the increasing prosperity of the country and the continuous improvement of the people's living standards,the country's investment in infrastructure is increasing year by year.Especially in the construction of bridges,there are a total of millions of bridges in the country,so the number of bridges in service has become more and more,the reinforcement of existing bridge components is imminent and carbon fiber is imminent Composite material has the advantages of light weight,high strength and strong oxidation resistance.It is widely used in structural reinforcement or bridge construction.In this paper,the flexural static load test of 7 prestressed CFRP reinforced concrete beams is carried out,and the cracking load,the ultimate load,the mid span deflection,the concrete strain of the beam top,the strain of the steel bar,the strain of the steel bar,the strain of the CFRP and the ultimate failure mode are compared.The initial preloading of the CFRP plate is analyzed.The impact of the stress on these mechanical properties.Some parameters obtained from the test are extracted,and the ANSYS simulation software is used to establish the numerical model for the prestressed CFRP reinforced concrete members.The main work is as follows:(1)first,introduce the commonly used reinforcement methods and the research status of carbon fiber reinforcement technology at home and abroad,and elaborate the significance of prestressed CFRP strengthening beams.(2)theoretical analysis and calculation of the force of CFRP flexural reinforced concrete beams.In this paper,the mechanism of several failure modes of the flexural reinforcement beam of carbon fiber board is analyzed,in which two kinds of failure modes of the end interface stripping and the middle crack peeling of CFRP flexural reinforcement beams are analyzed,and the reasonable calculation formula is put forward.(3)the concrete beams strengthened with different prestressed CFRP sheets are used to test the concrete beams.By comparing the test parameters such as the crack development trend,the cross deflection,the crack load,the yield load,the ultimate load and the failure form of the beam,the influence of the pre stress level on the flexural performance of the reinforced beams is analyzed.And the ultimate failure mode of concrete beams(4)a separate numerical analysis model is established by using ANSYS,including two models considering the bond slip between carbon fiber and concrete interface and without considering the bond slip between the carbon fiber and the concrete interface.The results of the two numerical simulation are compared with the experimental results.(5)combined with the theoretical research and formula calculation of a large number of scholars,the experimental results are compared with the results of ANSYS numerical simulation.The prestress on the prestress of CFRP reinforced concrete beams for non prestressed concrete beams is to significantly increase the cracking load of the beam,improve the yield load and ultimate load of the beam effectively,and apply prestress at the same time.It can delay the development of cracks and reduce the mid span deflection of beams.