1. Fujian Provincial Key Laboratory of Advanced Technology and Informatization in Civil Engineering,
Fujian University of Technology, Fuzhou 350118, China; 2. Fuzhou University, Fuzhou 350116, China
Abstract：Square composite-sectional concrete-filled stainless steel tubular (CFSST) column is a new type of composite member and has the potential for wide applications. In order to investigate the hysteretic behavior of the columns, eight beam-column specimens were tested under cyclic loadingThe main parameters were axial load ratio (0.05, 0.3 and 0.6), dimension ratio of inner tube to outer tube (0.42 and 0.67), types of columns (composite-sectional CFSST, double-skin hollow-interior CFSST and CFSST).A finite element model was developed to analyze the hysteretic behavior of the square compositesectional CFSST column. The influences of parameters on lateral load-displacement skeleton curves were investigated. The results show that, the hysteretic curves of square composite-sectional CFSST columns are relatively plump. The columns have higher bearing capacity, ductility and plastic energy dissipation capacity than the double-skin hollow-interior CFSST and CFSST columns. The bearing capacity of the square composite-sectional CFSST column increases dramatically with increasing yield strength of outer tube and sandwich concrete compressive strength or decreasing width-to-thickness ratio of outer tube, axial load ratio and slenderness ratio. The bearing capacity increases gently with increasing dimension ratio of inner tube to outer tube or decreasing width-to-thickness ratio of inner tubeIn most cases, the bearing capacity of square compositesectional CFSST can be increased by 2%～20% compared to that of the composite-sectional conventional concrete-filled steel tube.
