外加强环式圆钢管混凝土柱-钢蜂窝梁节点骨架曲线影响因素分析

Analysis of Influencing Factors on Skeleton Curves of ATCFCST-SCBJ

目的分析不同因素对外加强环式圆钢管混凝土柱-钢蜂窝梁节点荷载位移骨架曲线的影响,为合理设计该类节点提供依据.方法设计了参数不同的外加强环式圆钢管混凝土柱-钢蜂窝梁节点,采用有限元软件ABAQUS模拟这些节点在低周往复荷载作用下的受力过程,对比了各设计节点的荷载位移骨架曲线,模拟前采用已有试验数据对模拟方法进行验证.结果轴压比从0.2到0.4,骨架曲线仅在弹塑性下降段承载力略有明显变化,最大下降约15%;含钢率从0.063到0.132,梁柱线刚度比从0.2到0.33,骨架曲线变化明显,承载力最大分别增加71.6%和140%;加强环板宽度每增加20 mm,承载力提高约6%;开孔率从0到0.8,承载力最大降低约30%;孔间距从140 mm到260 mm,承载力最大提高约10%,梁端第一个开孔到柱的距离从150 mm到520 mm,承载力最大提高约15%.结论轴压比对外加强环式圆钢管混凝土柱-钢蜂窝梁节点荷载位移骨架曲线影响不明显;影响节点荷载位移骨架曲线的主要因素是含钢率和梁柱线刚度比;加强环板宽度对节点荷载位移骨架曲线影响不大;开孔率、孔间距、梁端第一个开孔到柱的距离对其荷载位移骨架曲线有一定影响,三者中开孔率影响最大、距离次之、孔间距最小.

In order to provide a basis for designing outer annular-stiffener type concrete filled circular steel tube-steel castellated beam joint（ ATCFCST-SCBJ）,the factors that influence the load-displacement skeleton curves w ere analyzed. ATCFCST-SCBJ w ith different influencing factors w eredesigned,and their loading-bearing process under low cyclic repeated horizontal loading w as simulated by using finite element softw are ABAQUS,and their load-displacement skeleton curves w ere also compared. Before simulating,the simulating method w as verified by the previous test result. It show s that w ith change of the axial compression ratio from 0. 2 to 0. 4,the change of bearing capacity of the skeleton curves obviously occurs only in the elastic-plasticity stage,the most of w hich has about 15% reduction; the bearing capacity of the skeleton curves also changes obviously w ith the change of steel ratio from 0. 063 to 0. 132 and the beam to column linear stiffness ratio changes from 0. 2 to 0. 33,the most of w hich increases 71. 6% and 140%,respectively; w ith increase of the w idth of reinforcement ring every 20 mm,the bearing capacity increases about 6%; w ith opening rate increase from 0 to 0. 8,the most bearing capacity decreases about 30%. With increase of the distance of tw o adjacent spacing hole center from 140 mm to 260 mm,the maximum bearing capacity increases about 10%; the maximum bearing capacity increases 15% w ith change of the distance betw een the first spacing hole center and the column from 150 mm to 520 mm. It can be concluded that the axial compression ratio is not an important factor that influences the skeleton curve of ATCFCST-SCBJ; the steel ratio and the beam to column linear stiffness ratio are the tw o important factors. But the w idth of the stiffener ring has no large influence; the opening rate,the hole spacing and the distance of the first hole center at beam end to the column have some influence on it,of w hich the first one has the biggest influence,the second one has smaller influence and the last one has the smallest influence.