Numerical Analysis On External Prestressing CFRP Concretethin-wall Box Girder Flexural Performance

External prestressing carbon fiber reinforced polymer sheets concrete thin-wallbox girder combining the superiority of the technology of External prestressing andthe super performance of carbon fiber reinforced polymer sheets, And it is also inaccord with the requirements of environment protection and sustainable humandevelopment, And it could provide effective assurance to it is spread and applicationin the bridge structures. On the basis of the research to experimental on flexuralbehavior of external prestressing carbon fiber reinforced polymer sheets concretethin-wall box girder, this thesis analyzed the parameters of experimental box girder’snumerical analysis by using ANSYS. The main research results are as follow:1. By means of setting up experimental box girder’s finite elment model, thewriter proved that the numbers load-deflection curves, load-stress increment curvesand mid-span box girder roof and floor concrete strain distribution from analyzingare in good agreement with the experimental data. And this thesis also proved thatwith choosing the appropriate element type and consititutive relation, we couldexactly simulate the overall process of external prestressing carbon fiber reinforcedpolymer sheets concrete thin-wall box girder’s load and deformation by usingANSYS.2. Through the parameters analysis of the initial tensioning prestressed, wecome to the conclusions: The enhancement of initial tensioning prestressed lead tothe enhancement of box girder’s cracking load significantly, increased range is96.4%; the enhancement of initial tensioning prestressed lead to the reduction ofultimate stress increment, but the effective availability is increased to97.5%in0.65fptk and anti-arch degree meet standard requirement, which take full use of. theenhancement of initial tensioning prestressed reduce the shear leg effect. We suggestthat experimental box girder’s initial tensioning prestressed should be controlled in0.65fptk.3. Through the parameters analysis of the carbon fiber reinforced polymersheets’ layout form, we come to the conclusions: In the initial tensioning prestressedof0.3fptk and using diaphragm deviation block, single-fold line layout form boxgirder’effective utilization of carbon fiber reinforced polymer sheets is lower thanthe double-fold line layout form box girder’effective utilization of carbon fiberreinforced polymer sheets. From what has been discussed above, Set up deviation block reasonablely could give full paly to the carbon fiber reinforced polymersheets’s effective utilization.4. Through the parameters analysis of the span-depth ratio, we come to theconclusions: The enhancement of span-depth ratio lead to the reduction of boxgirder’s cracking load and ultimate load, cfrp stress increment decrease at the samedeflection and ultimate stress increment increase; The bigger span-depth ratio, thesmaller shear leg effect.5. Through the parameters analysis of the reinforcement ratio, we come to theconclusions: The enhancement of floor tensil reinforcement’ reinforcement ratiohave little effect on cracking capability, it can improve yield load and ultimate load,at the same time, the ultimate deflection and cfrp stress increment decrease;Reinforcement ratio have more effective on shear lag of floor plate than top plate atthe elastic range; The enhancement of floor cfrp reinforcement ratio lead to theenhancement of box girder’s cracking load and ultimate load, at the same time, thecfrp ultimate stress increment decrease and go against the effective utilization rate ofCFRP.