方形复合不锈钢管混凝土柱滞回性能研究

方形复合不锈钢管混凝土柱是一种新型组合构件，具有广阔应用前景，为研究其滞回性能，以轴压比(005、03和06)、内外管尺寸比(042和067)、柱类型(复合不锈钢管混凝土、中空夹层不锈钢管混凝土、不锈钢管混凝土)为主要参数进行8个压弯试件在往复荷载作用下的试验研究，建立方形复合不锈钢管混凝土柱滞回性能分析的有限元模型，考察各参数对侧向荷载 位移骨架线的影响规律。研究结果表明：方形复合不锈钢管混凝土柱的滞回曲线较为饱满，且比中空夹层不锈钢管混凝土柱和不锈钢管混凝土柱具有更高的极限承载力、延性和塑性耗能能力。随着外管屈服强度、夹层混凝土抗压强度的增加或者外管宽厚比、轴压比、长细比的减小，方形复合不锈钢管混凝土柱极限承载力显著增加，随着内外管尺寸比的增加或者内管径厚比的减小，极限承载力有所增加，但增加幅度不大。多数情况下，方形复合不锈钢管混凝土比复合普通钢管混凝土极限承载力高2%～20%。

Hysteretic behavior of square composite sectional concrete filled #br# stainless steel tubular columns

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 loadingThe 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 composite sectional 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 tubeIn most cases, the bearing capacity of square composite sectional CFSST can be increased by 2%～20% compared to that of the composite- sectional conventional concrete-filled steel tube.