摘要
共进行了10根不同长细比的钢管混凝土哑铃形轴压长柱(5根强轴向破坏,5根弱轴向破坏)的试验研究。对于沿强轴方向失稳破坏的试件,通过在弱轴方向焊接波形钢板以加大其抗弯刚度来实现,试验结果表明这一方法是可行的。与单圆管轴压长柱相似,哑铃形轴压长柱试件的极限承载力和弹塑性阶段切向刚度均随着试件长细比的增加而减小。但相同长细比情况下,与单圆管长柱弹性失稳破坏不同,哑铃形长柱属弹塑性失稳破坏。提出了哑铃形轴压长柱的非线性有限元计算方法,并进行了长细比对极限承载力影响的参数分析。研究结果表明:哑铃形轴压长柱的稳定系数与单圆管的不同,但沿强轴、弱轴向失稳的极限承载力随长细比变化而变化的规律基本一致,提出了将二者统一的稳定系数简化计算公式。
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 ratio on its load-carrying capacity is analyzed by parametric studies. It is shown that the stability coefficient of dumbbell-shaped long CFST columns is different from that of long CFST columns of single tube section. However, the rules of load-carrying capacity in the weak-stress-axis and strong-stress-axis directions for dumbbell-shaped long CFST column, varying with the slenderness ratio, are similar. A simplified formula to calculate the stability coefficient is presented by unifying the rule in two directions.
出处
《工程力学》
EI
CSCD
北大核心
2008年第4期121-127,133,共8页
Engineering Mechanics
基金
福建省基础性研究计划重大项目(2003F007)
关键词
钢管混凝土
哑铃形
轴压
长柱
极限承载力
有限元
concrete-filled-steel tube
dumbbell shape
axial load
long column
load-carrying capacity
finite element
