型鋼-方鋼管混凝土軸壓短柱非線性分析
談忠坤1,2,3，李剛2，汪幼林2，梁波2，郭棋武2，田代亮2
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（1 湖南大學土木工程學院， 長沙 410012； 2 湖南中大建設工程檢測技術有限公司, 長沙 410205；3 湖南中加土木工程加固技術有限公司, 長沙 410205）
［摘要］采用ABAQUS有限元軟件對型鋼-方鋼管混凝土軸壓短柱的荷載-變形曲線進行了有限元分析，探討了型鋼-方鋼管混凝土軸壓短柱、等截面普通方鋼管混凝土軸壓短柱、等截面且等體積含鋼率的型鋼-圓鋼管混凝土軸壓短柱的內(nèi)力變化情況。分析結果表明：三種短柱中型鋼-圓鋼管混凝土軸壓短柱的極限承載力最大且延性最好；與等截面普通方鋼管混凝土軸壓短柱相比，型鋼-方鋼管混凝土軸壓短柱中核心混凝土縱向應力有所增長，鋼管屈服后縱向應力降低速率、環(huán)向應力增加速率減緩，鋼管對核心混凝土的約束作用減??；與等截面且等體積含鋼率的型鋼-圓鋼管混凝土軸壓短柱相比，型鋼-方鋼管混凝土軸壓短柱角部端點的約束效果最明顯，鋼管中點的約束效果最弱，型鋼-圓鋼管對核心混凝土的整體約束最強，型鋼屈服后縱向應力略低于其屈服強度，且型鋼的翼緣部分抗壓強度比腹板部分的抗壓強度高；等型鋼含量情況下，隨著翼緣長度b與腹板高度h比值的增大，軸壓短柱的極限承載力越來越低，當b/h=0，即十字形鋼骨-方鋼管混凝土軸壓短柱承載力最高；等體積含鋼率下，普通方鋼管混凝土柱軸壓短柱承載力最低，隨著型鋼截面面積As與方鋼管截面面積At的比值的增大，軸壓短柱的極限承載力先增后降，當As/At≈0.8時，承載力達到最大值。［關鍵詞］普通方鋼管混凝土; 型鋼-方鋼管混凝土; 型鋼-圓鋼管混凝土; 極限承載力; 有限元法; 非線性中圖分類號：TU375 文獻標識碼：A 文章編號：1002-848X(2016)04-0062-06
Nonlinear analysis of axially loaded steel reinforced concrete-filled square steel tubular stub columnsTan Zhongkun1,2,3, Li Gang 2, Wang Youlin2, Liang Bo2, Guo Qiwu2, Tian Dailiang2(1 School of Civil Engineering, Hunan University, Changsha 410012, China; 2 Hunan Zhongda Construction Engineering Testing Technology Co., Ltd., Changsha 410205, China;3 Hunan Zhongjia Civil Engineering Strengthening Technology Co., Ltd., Changsha 410205, China)Abstract:The finite element analysis on load-deformation curve of steel reinforced concrete-filled square steel tubular (SR-CFST) stub columns was carried out by finite element software ABAQUS. The changes of internal forces in SR-CFST, ordinary concrete-filled square steel tubular(CFST) stub columns with the same section and steel reinforced concrete-filled circular steel tubular (SR-CFCT) stub columns with the same section and steel ratio were discussed. The results were listed as follows: the ultimate bearing capacity and ductility of SR-CFCT stub columns are best in the three stub columns; compared with CFST stub columns with the same section, the axial stress of concrete in SR-CFST stub columns increases slightly. After yield, both the decrease rate of axial stress and increase rate of perimeter stress of steel tube weaken slowly and the confinement effect from steel tube to concrete also weakens; compared with SR-CFST stub columns with the same section and steel ratio, the confinement effect of SR-CFST is most obvious in extreme point but weakest in steel middle point. The confinement effect from steel tube to concrete is strongest in SR-CFCT. The axial stress is slightly lower than its yield strength and the compressive strength of steel reinforced in flange is higher than that of web; under the same section steel condition, with the increase of the ratio of flange length b and web height h, the ultimate bearing capacity of stub columns under the axial compression is lower and lower. When b/h=0, the bearing capacity of axially loaded cross SR-CFST stub columns is highest; under the same volume steel ratio, the bearing capacity of CFST stub columns is lowest and the bearing capacity first increases then decreases with the increase of ratio of cross section area As of shape steal and cross section area Atof square steel tube. When As/At≈0.8, the bearing capacity reaches the maximum value.Keywords:concrete-filled square steel tubular; steel reinforced concrete-filled square steel tubular; steel reinforced concrete-filled circular steel tubular; ultimate bearing capacity; finite element method; nonlinear
作者簡介：談忠坤，博士，高級工程師，Email：175336988@qq.com。
