长细比对方钢管混凝土柱受力性能的影响

以基本试件(BASE)为基础设计3个不同长细比的ZG试件并进行非线性有限元分析,采用在钢管和混凝土之间加入粘接单元的方法。分析得知:柱长细比是方钢管混凝土柱设计的主要影响因素。柱长细比越大,柱承载力越低,因此长细比可适当减小。此外,在方钢管的底部和底角部存在应力集中现象,应力集中区域大约在柱高1/3范围内。对方钢管的底部应加大刚度,柱底角部应加强施焊。混凝土压碎破坏多发生在柱底部,因此在管内混凝土的施工过程中,要保证混凝土柱底浇筑密实。

EFFECT OF SLENDERNESS RATIO ON BEHAVIOR OF SQUARE CONCRETE-FILLED STEEL TUBULAR COLUMN

Based on basic specimens, the three ZG square concrete-filled steel tubular columns are designed and it is analysed by nonlinear finite element with felt element between steel pipe and concrete. Slenderness ratio may be reduced properly,because slenderness ratio is more big,the carrying capacity is more low. The stress poll will appear in the bottom and corner of column, the stress poll is in one-third of height of column. Therefore the stiffness of bottom of column must be enhanced, the corner of column must be welded greatly. Because the concrete crack is in the bottom, in the course of the concrete construction,it should guarantee the concrete of the column bottom close-grained.