Study Of Seismic Performance And Axial Load Bearing Capacity For Acid Rain Environmental Corroded Concrete Filled Steel Tubular Columns

The structure of the bearing capacity and stiffness are influenced by acid rain corrosion, On the basis of the experimental research of our group, the mechanical properties of concrete filled steel tubular column under cyclic loading and axial compression loading were analyzed respectively, which is corroded by acid rain. It presents the formulation between the seismic performance and corrosion rate, as well as the axial load bearing capacity. the main work is as follows:(1) The finite element model of concrete filled steel tubular column under cyclic loading is established, the reliability of the model was verified by others test results.(2) According to the corroded steel test result that the elastic modulus and yield strength is declined, through Substituting the elastic modulus and yield strength reduction formula in the steel and concrete constitutive model, A finite element model of acid rain corrosion concrete filled steel tubular column under cyclic loading is established which considers corrosion damage, compared to our group test results, it verified the reliability of the model.(3) After parameters analysis on acid rain corrosion concrete filled steel tubular column under cyclic loading, The main changing parameter is corrosion rate(?= 0%, 5%, 10%, 15%, 20%, 25%, 30%) and axial compression ratio(n= 0.2,0.4,0.5),the variation between seismic performance index value and corrosion rate is studied, such as yield load, yield displacement, ultimate load, ultimate displacement, ductility factor, stiffness and cumulative hysteretic energy. And return to calculate relationship between the seismic performance of the index value and the corrosion rate.(4) A finite element model of acid rain corrosion of circular concrete filled steel tubular columns considering corrosion damage unedr axial compression loads is established, By comparison with the experimental results, it demonstrates the effectiveness of the finite element model. On this basis, the parameter analysis of acid rain corrosion concrete filled steel tube column under axial compression load is carried on, According to the unified theory of concrete filled steel tube, the simplified formulation of acid rain corrosion concrete filled steel tube under axial load is obtained, compared to the test results, the simplified formulation of bearing capacity is lower, indicating that the simplified formulation is safe.