钢管混凝土哑铃形轴压长柱极限承载力研究-可持续与创新桥梁工程.PDF

25 4 Vol.25 No.4 2008 4 Apr. 2008 ENGINEERING MECHANICS 121 1000-4750(2008)04-0121-07 * 1 2 (1 350002 2 350002) 10 (5 5 ) TU398 A RESEARCH ON LOAD-CARRYING CAPACITY OF CONCRETE-FILLED-STEEL TUBULAR DUMBBELL-SHAPED LONG COLUMNS UNDER AXIAL LOADS * 1 2 CHEN Bao-chun , SHENG Ye (1. College of Civil Engineering, Fuzhou University, Fuzhou, Fujian 350002, China; 2. College of Transportation, Fujian Agriculture and Forestry University, Fuzhou, Fujian 350002, China) Abstract: Experiments of 10 concrete-filled-steel tubular (CFST) dumbbell-shaped Long columns with various slenderness ratio subjected to axial load were carried out, in which 5 specimen were failed in the strong-stress-axis direction; another 5 were failed in the weak-stress-axis direction. It is proved by the test that the failure of dumbbell shaped specimen in strong-stress-axis direction can be realized by welding corrugated steel webs in its weak-stress-axis direction to increase flexible rigidity in this direction. Similar with the long columns of single tube section, the load-carrying capacity and the elastic-plastic tangential stiffness of CFST dumbbell-shaped long columns decrease with the increasing of slenderness ratio. But elastic-plastic instability occurred on dumbbell-shaped long columns instead of the elastic instability in one of single tube section with same slenderness ratio. A nonlinear finite element method is provided for dumbbell-shaped long column, and the influence of slenderness ra