The Oretical Study And Finite Element Analysis On Prestressed CFRP Strengthened Concrete Continuous Beam Under Secondary Load

Carbon Fiber Reinforced Polymer(CFRP)reinforcement technology led into China from the last century in 90 s,with 20 years of development CFRP reinforcement technology has become a mature technique,is more convenient and efficient compared with the traditional way of reinforcement technology.There are still some problems need to be improved at present:1.when the yield of steel,CFRP just reaches 30% of it tensile strength,superior tensile properties of carbon fiber material is far from played out,for the use of expensive carbon fiber cloth is so waste.2.The reinforcement effect are not obvious on failure of components and two stress reinforcement effect,because of the lag strain.but the further development of carbon fiber buffett can not effectively suppress the crack,also need to further expand the cracks can exert its tensile properties.Therefore,it is necessary to introduce the concept of prestress,apply 10%-30% prestress to the carbon fiber cloth before sticking,and then sticking,curing and unloading,so as to restrain the crack development and develop the performance of the carbon fiber cloth.The main contents of this paper are as follows:1)Based on relevant references,summarizing the existing reinforced by prestressed CFRP single span concrete beam test data and related formula,according to the difference of single span beam and continuous beam strengthened by CFRP and one by the difference of force and the two force,a force are derived,two times of stress the prestressed and non prestressed CFRP sheet bending bearing capacity formula of reinforcement concrete continuous beam section,and compared with the theoretical formula and the experimental data,verify the applicability of the formula.2)According to the analysis on the main factors influencing the bearing capacity of the theoretical formula,calculate the variables on the two impact force curve of bearing capacity of concrete continuous beam when the ultimate flexural reinforcement of prestressed CFRP sheets,research shows that the bearing capacity of prestressed CFRP sheets on the continuous beam has greatly improved,and the ability to influence offset two force.3)The plastic hinge method is used to deduce the key parameters such as the momentdistribution coefficient of concrete continuous beam strengthened with prestressed CFRP cloth under two load.4)Bearing capacity of reinforced concrete continuous beam,the stress and deformation of the simulation results of different variables CFRP sheets by using finite element software ABAQUS,and the simulation data,the theoretical data and reference test data for comparison,the results show that the theoretical capacity of ABAQUS finite element analysis calculation results and simulation results of bearing capacity value is anastomosis.