Hysteretic Behavior Of Concrete-Filled Steel Tubular Columns Brace Under Varible Axial Force

Confining effect between steel and. concrete is used in concrete-filled steel tubular(CFST), so it has high bearing capacity, plasticity, ductility and fire-resistant performance. CFST have been used in high rises and large-span bridges. The study on the strength and performance of circular CFST have been carried in many countries, but research on the hysteretic behavior of circular CFST under variable axial force is very limited. The research is processed in this paper, it has significant academic value and engineering application value.The main research work can be stated as follows:1. the constitutive relations of concrete and steel are put up.2. Inelastic finite element .analysis of CFST brace is presented. Based on the theory of inelastic finite element considering material and geometrical nonlinearity, inelastic hysteretic model is set up. The Fortran program is developed.3. Typical CFST brace elements are designed. Research on the hysteretic behavior of CFST brace element is carried through by using the program developed. Practical design suggestions are also made.In summary, the research on the hysteretic behavior of CFST brace may provide reasonable and scientific design gist for engineering design.