【作者】 孙潮；

【导师】 陈宝春；

【作者基本信息】 福州大学 ， 结构工程， 2009， 博士

【摘要】 钢管混凝土格构柱与桁拱均属于空腹结构,由较小直径的钢管混凝土杆件与联结件组成,具有较大的抗弯刚度,得到了广泛的应用。但其设计计算理论还不完善。为此,本文对钢管混凝土格构柱和桁拱轴力弯矩相关曲线开展研究,主要研究工作如下：(1)引入连续化假定和缺陷杆有效轴压刚度,将钢管混凝土空腹结构等效成实腹杆结构进行有限元分析,并用FORTRAN语言编制了程序。在满足分析精度的同时,提高了钢管混凝土空腹结构有限元分析的效率。(2)进行了包括偏心受拉的钢管混凝土格构短柱极限承载力的试验研究和理论分析。研究表明,钢管混凝土格构柱轴力弯矩相关曲线必须考虑拉压不等强的特点,国内钢管混凝土设计规程(CECS 28:90、JCJ 01-89和DL/T 5085-1999)的有关算法存在不足之处。应用有限元程序进行了钢材和混凝土强度、含钢率、长细比等参数的分析,得到了钢管混凝土格构柱轴力弯矩相关曲线方程。分析了相关屈曲对钢管混凝土格构柱极限承载力的影响,提出了考虑相关屈曲影响的格构柱极限承载力的简化算法。(3)以钢管混凝土抛物线桁拱L/4截面的内力为名义内力,分析了其稳定系数的特点。得到其强度破坏和弹塑性失稳破坏的界限长细比,弹塑性失稳破坏和弹性失稳破坏的界限长细比,给出将钢管混凝土抛物线桁拱稳定系数按三段(强度破坏段、弹塑性失稳段和弹性失稳段)表示的表达式。提出了钢管混凝土桁拱的轴力弯矩相关曲线方程。分析了相关屈曲对钢管混凝土桁拱极限承载力的影响,提出了考虑相关屈曲影响的桁拱极限承载力的简化算法。(4)根据钢管混凝土格构柱的稳定系数和实际工程统计得到的格构柱回转半径与截面高度的关系,给出了偏于安全的钢管混凝土格构柱剪力表达式。讨论了钢管混凝土桁拱腹杆内力取值问题。将钢管混凝土格构柱考虑剪切柔度系数的稳定计算方法推广到钢管混凝土桁拱,得到了考虑剪切变形影响的钢管混凝土桁拱稳定极限承载力的计算方法。更多还原

【Abstract】 Both of concrete filled steel tubular (CFST) laced columns and truss arches are cancelled structures, compositing of smaller diameter CFST member and connection members. They have great bending rigidity and are widely used in civil engineering. However, the design calculation theory for such structures is not mature. Therefore, researches on correlation curves between axial force and bending moment of CFST laced columns and truss arches are conducted in this paper. The main research works have been carried out as follow:1) Based on the continuous assumption and conception of efficient axial compressive rigidity, a simplified FEM was proposed, in which CFST cancelled structures was stimulated as solid bar structure and the correlation buckling of the structures was taken into account. Based on this FEM, a program was edited by FORTRAN language, which improves the computation efficiency with enough precise analysis results.2) Experimental and theoretical research on correlation curves between axial force and bending moment of CFST laced columns including eccentrically tensile loads were carried out. The differences between tensile strength and compression strength of CFST member should be considered in the calculation of its correlation curves. It was pointed out that correlation curves in design criteria for CFST structure in China had a deficiency. The influences of concrete and steel strength, steel ratio and slenderness ratio on correlation curves were studied by FEM and correlation curves equation of CFST laced columns was presented. The influence of correlation buckling on ultimate load-carrying capacity of CFST laced columns was studied and a corresponding simplified calculation method was proposed.3) Taking L/4 section inner force of parabolic CFST truss arches as nominal inner force, the feature of stability factor of parabolic CFST arches was analyzed. Its critical slenderness ratio between strength failure and elastic-plastic buckling and the critical slenderness ratio between elastic-plastic buckling and elastic buckling were obtained. The expression of stability factor of CFST parabolic truss arches was divided into three parts (strength failure part, elastic-plastic buckling part and elastic buckling part) and proposed. Correlation curves equation of CFST truss arches was presented. The influence of correlation buckling on ultimate load-carrying capacity of CFST truss arches was studied and a corresponding simplified calculation method was proposed.4) Based on the stability factor of CFST laced columns and the relationship between gyration radius and section height by statistics, the safe shear formula of CFST laced columns was proposed. The calculation method for the inner force of the web member in the truss arches was presented. The stability analysis method in CFST laced columns considering the shearing flexibility factor of the laced members was adopted in predicting the ultimate load-carrying capacity of CFST truss arches, and a corresponding calculation method was gained.更多还原