考虑荷载偏心率的双肢钢管混凝土格构柱力学性能研究

RESEARCH ON THE BEHAVIOR OF CONCRETE FILLED STEEL TUBULAR( CFST)DOUBLE-LIMB LATTICED COLUMNS CONSIDERING LOAD ECCENTRICITY RATIO

基于有限元软件ABAQUS建立双肢钢管混凝土格构柱的分析模型,对已有试验的荷载-变形全过程进行数值模拟,有限元分析结果与试验结果吻合良好。在此基础上,进行了双肢钢管混凝土格构柱平面内、外受力性能分析以及影响因素分析。研究结果表明:在加载初期,构件平面内外方向的刚度相当,随着荷载的增加,构件平面外方向比平面内方向提前进入弹塑性阶段,使得平面外荷载提前到达峰值荷载,延性较差。此外,荷载偏心率和换算长细比的增加都会使双肢钢管混凝土格构柱的受压极限承载力下降,不过相对于换算长细比的增加,荷载偏心率的增加对极限承载力下降的影响更为显著。

Based on the finite element software ABAQUS,the analysis model of concrete filled steel tube with double limb latticed column was established to numerically simulate the whole load-deformation process of existing test. The calculated results were in good agreement with the experimental results. Furthermore,the mechanical characteristics in and out the plane and parameter influence of concrete filled steel tube with double limb latticed column were analyzed. The research results showed that in the initial loading stage,the in and out the plane stiffness of the members was about the same. However,with the increase of load,the out-of-plane direction entered the elasticplastic stage earlier than in-plane,which made out-of-plane load reach its peak value in advance,its ductility was poor. In addition,the increase of the load eccentricity ratio and conversion slenderness ratio could make the ultimate bearing capacity of concrete-filled steel tube lattice column drop. but compared with the conversion slenderness ratio,the influence of eccentric load on the ultimate bearing capacity was more significant.