Experimental Research and Damage Model of Square Concrete-Filled SteelTube Subjected To Cyclic Loading

摘要

Nine square concrete-filled steel tube (CFT) columns with different axialload level (0.165～0.517), slenderness ratio (10.82～32.88), and constraining factor(0.61～1.51) were tested under a constant axial load and cyclically varying lateralloads. The experimental results showed that the hysteresis curves of the test columnsare plump in shape without significant pinch phenomenon, which means that thestiffness and strength of the columns deteriorated slowly and the columns have agood ability of energy dissipation. Based on the analysis of the experimental data, theexpressions of maximum strength Qu and ultimate deformation δu of square CFTcolumn are proposed. Park damage index is employed for CFT columns seismicdamage evaluation. According to the test data, the value of parameter β is determined.