Research On Behavior Of Thin-Walled Steel Tube Colums With Concrete-Filled Under Axial Compression

In this paper, the properties of concrete-filled thin-walled steel tubular columns (CFTST) under axial compression are studied by using of ANSYS, which are based on others experimentation. The main content is follows.1. Some questions about ANSYS simulation are discussed, such as the types of units identified, the constitutive material selected, mesh density, strengthen the convergence of methods, and the methods adopted in this paper are determined.2. The specimens mainly include circular and square short columns steel tubular. The comprehensives parametric study is carried out to investigate the behavior of CFTST. The research results show that many factors, such as, regressing the improved coefficient of concrete and confined coefficient, diferent cross-sections, and the grade strength of concrete, have diferent effects on the increasing strength of concrete.3. The previous test was quoted, and designed some of the specimens about the CFTST. The curves about the relationship betweenξand k_c are confirmed by using of the ANSYS finite element simulation. The axial compressive ultimate strength formulas of CFTST are proposed based on analyzing the thesis and foreign experiment data, and the formulas are compared to other codes formulas. The factors of the limit of the width-thickness ratio of steel to concrete, the strength of material relationship to match, size effect are reseached more further, and has drawn some interesting conclusions for work.4. The mechanical properties of the slender of thin-walled steel tube colums with concrete filled are also studied. At first the the strength calculation formula of the Euler Colum is introduced and considering the effect of local buckling of steel sheets and initial curving being considered. And then the influence of the factors including slenderness, and material strength on the capacity are researched.