Nonlinear Analysis On Unbonded Flexural Members Partially Reinforced With Cfrp Tendons

Carbon Fiber reinforcement polymer tendon(FRP tendon) has many advantages such as corrosive resistance,high strength and lightweight.It can replace steel bar in concrete structure, which can avoid deterioration of bearing capacity and durability due to corrosion of steel bar and reduce the maintenance cost.4 unbonded partially prestressed CFRP reinforced concrete simple beams are designed, which are reinforced with CFRP unbonded tendons and a certain number of non-prestressed reinforcements.The flexural performance of this kind of beam is investigated.On the basis of analysis on test data,the calculation formula of stress increment of CFRP tendon in the beam during serviceability and ultimate limit state.The calculation formula of short-term stiffness of the beam is presented under characteristic combination of load based on test curve of loaddeflection and the twi-line theory.At the same time,the law of distribution of crack and the calculation method of the average spacing of crack are explored.Nonlinear finite element analysis on the mechanical performance of unbonded partially prestressed CFRP reinforced concrete simple beam under load is made by using ANSYS Software.The modeling method,the unit,constitutive relation of material and solving methods are illustrated.The ultimate bearing capacity of beams,the deflection of beam,the normal stress and strain of beam and the stress variation of CFRP tendons are analyzed.The calculated results and the test results are compared and they are in good agreement,which verifies that the test result is correct.