Research On Mechanical Behaviour Of The Column Of Concrete Filled Stiffened Double Skin Steel Tubes

The concrete-filled steel tubes structures is a promising development structure that can adapt to the modern engineering structure of large-span, tall, and overloaded development and bear the need to withstand harsh conditions; meet the industrialized requirements of modern construction technology. The concrete-filled steel tubes has become increasingly widely used in industrial plants, high and ultra high-rise buildings, bridges and underground structures and become an important developing direction in structure engineering science. Compared with the concrete-filled steel tube, columns of Concrete Filled Double Skin Steel Tubes maintain the traditional strengths and it is also has advantages of large cross-section and bending stiffness, light weight, fire resistance and better seismic performance than the concrete-filled steel tube and so on. When the steel pipe is thin, the column prone to buckling. In order to improve the mechanical behaviour of concrete filled double skin steel tubes of stiffening rib, steel outer walls of double skin concrete are filled with stiffening rib to change the structure of a new type - the column of concrete filled stiffened double skin steel tubes.According to the experimental data of associated literature, this paper analyze mechanical properties of the column of concrete filled stiffened double skin steel tubes by using the finite element software ANSYS. Firstly,through the calculation and analysis of the series of two groups of seven specimens, the main research focuses on mechanical behaviour of concrete filled stiffened double skin steel tubes columns under axial compression, simplify formula for calculating the bearing capacity of concrete filled double skin steel tubes columns with axial compression, and establish formula for calculating the bearing capacity of concrete filled stiffened double skin steel tubes columns with axial compression.According to the data of finite element simulation and the data in the literature,the paper amended the formula for calculating the bearing capacity of concrete filled stiffened double skin steel tubes columns with axial compression by regression analysis.At last, through the calculation and analysis of the series of three groups of ten specimens, the research focuses on mechanical properties of the column of concrete filled stiffened double skin steel tubes under the horizontal force and the axial force to obtain some practical reference to result in the conclusion for engineering design.