Abstract：
Based on the finite element analysis of lightweight concrete filled double round skin short column, this paper aims at studying the mechanical property of lightweight aggregate concrete filled double-skin steel tubular middle long column by establishing the model of middle-long column with ANSYS to carry out the stress calculation and result analysis. According to the main factors that influence the mechanical properties of the medium-long column and the existing calculation formula, the formula for calculating ultimate bearing capacity is corrected. The results of the modified formula are coincident with ANSYS. By analyzing the main factors concerned when the formula is corrected, the results are as follows: the ultimate load and ductility decreases with the increase of slenderness ratio; ductility decreases with decrease of concrete strength, but it has little influence on the ultimate load.
