Research On Fatigue Performance Of Self-locking Prestressed CFRP Strips Strengthened Concrete Bridges

Due to environmental erosion and heavy traffic,existing Bridges usually work with damage during their service.This thesis uses ABAQUS2018’s large-scale general finite element software to conduct a finite element simulation analysis based on the fatigue experiment of small and medium-span concrete beams under the combined action of environment and load.The comparison of fatigue simulation calculation data and experimental data is used to verify The finite element method in this paper is correct.On this basis,a finite element analysis method is used to conduct a finite analysis of the fatigue performance of concrete beams reinforced with self-locking pre-stressed CFRP strips under heavy load traffic.Then,based on this finite element model,a comparative analysis of the fatigue performance of the concrete beams strengthened with prestressed CFRP strips under the influence of multiple factors under general heavy load is carried out.The research results of this paper are as follows:(1)The finite element simulation analysis of the fatigue test of small and medium-sized span concrete beams under the combined action of environment and load in reference [34] was carried out,and the numerical simulation results obtained were compared with the experimental results in reference [34].The accuracy and high precision of the finite element analysis method were successfully demonstrated.(2)In this paper,using the verified finite element analysis method and the self-locking anchor system,the fatigue performance of 8 concrete beams strengthened with self-locking prestressed CFRP strips under different heavy loads and different damage degrees are simulated and analyzed.This paper discusses the influence of different heavy loads and damage degrees on the fatigue performance of concrete beams,and compares and analyzes the relationship between ultimate load,fatigue times and mid-span displacement of the beams,and the difference of fatigue life of each concrete beam.(3)The fatigue performance of self-locking prestressed CFRP strips reinforced concrete beams under general heavy loads under the influence of multiple factors is compared and analyzed by changing the number of layers,width and different high prestress levels of the finite model.The differences of ultimate bearing capacity,flexural rigidity and fatigue life of concrete beams under the influence of various factors are investigated,the influence degree and possible existing law of these factors on the fatigue performance of concrete beams are studied,and some Suggestions for strengthening prestressed CFRP strips are put forward.