Study on composite T-shaped concrete filled steel tubular columns under eccentric compression

Based on the summary of various types of special shaped concrete-filled steel tubular columns in practical application,composite T-shaped concrete-filled steel tubular column was presented in this paper.Eighteen composite T-shaped concrete-filled steel tubular columns were designed and manufactured with considering several experimental parameters such as the slenderness ratio and the eccentricity.Eccentric compression tests were carried out,and the mechanical behavior of composite T-shaped concrete-filled steel tubular columns with the slenderness ratio of 16 λ ≤ 40 were investigated,focusing on the load-strain relationships,load-column deflection relationships,failure modes of the specimens,and the effects of different influencing parameters on the eccentric compression properties of the specimens.Based on the existing methods in both domestic and foreign codes,the practical design formula for the eccentric compression bearing capacity of composite T-shaped concrete-filled steel tubular columns was derived through the regression analysis of experimental data.The results show that the eccentric compression columns are dominated by flexural buckling,and the greater the slenderness ratio is,the more obvious the characteristic of flexural failure is.The studies show that the two parts of composite T-shaped concrete-filled steel tube column can work together very well with good mechanical properties.The formula could be valuable for engineering design.