【摘要】 目的设计一种新型方钢管混凝土分体短柱(简称分体短柱),研究其破坏过程和受力性能,以便为分体短柱轴心受压设计提供理论依据.方法拟以分体短柱的套箍系数、截面形式、混凝土强度等级、分体短柱含钢率为试验参数,设计了8根方钢管混凝土短柱,并对其破坏形式和特征、其荷载-应变关系曲线、肋板的荷载-应变关系曲线以及承载力的敏感影响因素进行深入的研究.结果分体短柱和普通方钢管混凝土短柱(以下简称普通短柱)相比较破坏时受力相对均匀,呈现多处鼓曲.普通短柱后期承载力约为分体短柱的78%~82%.当分体短柱核心区混凝土强度由C30提高到C60时,其屈服强度提高约35%,荷载-应变关系曲线有明显的下降段.当含钢率由0.10提高到0.16时,其后期承载力约提高30%.套箍系数由1.02提高到1.80时,其后期承载力约提高30%.结论混凝土强度能够明显提高分体短柱极限承载力,但试件塑性变形能力降低.含钢率、套箍系数对承载力提高和塑性变形能力改善均有明显的作用.更多还原

【Abstract】 A new type of CFST split short column was designed to study its failure process and mechanical behavior,in order to provide some theoretical references for designing the split short column under axial compression. Taking ferrule coefficient,cross section form,strength grade of core concrete and steel ratio of the split short column as test parameters,8 square CFST short columns were designed. The damage form,load-strain curves of steel tube and rib,and sensitive factors for bearing arestudied. It is found that in comparison with the ordinary CFST,the split short column has relatively uniform stress by damage; but several bulges occur. The bearing capacity of the ordinary CFST is about 78 % ~ 82 % of the split short column. When the strength grade of concrete increases from C30 to C60,the yield strength increases about by 35 %. The load-strain curve declines obviously. When the steel ratio increases from 0. 10 to 0. 16,the bearing capacity of the split short column increases by 30 %. The split short column bearing capacity increases by 30 % with increase of the ferrule coefficient from 1. 02 to 1. 80. Conclusion is that the concrete strength grade can increase the bearing capacity of the split column obviously. But its plastic deformation ability decreases. The steel ratio,the ferrule coefficient can obviously improve the bearing capacity and ductility.更多还原