钢筋混凝土Z形截面柱正截面承载力及延性研究

发布时间：2018-06-23 06:44

本文选题：Z形截面异形柱 + 正截面承载力　；参考：《天津大学》2013年博士论文

【摘要】：混凝土异形柱框架结构由于其在建筑布置中的优越性而被广泛地应用于建筑设计中。但作为异形柱构件基本截面形式之一的Z形截面柱却没有在异形柱规程中体现。本研究利用自编程序及ANSYS大型有限元程序对Z形截面柱的正截面承载力、截面延性进行全面分析，研究包括材料特性、截面尺寸以及加载方式等多方面因素对柱截面承载力及延性的影响。本文用ANSYS大型有限元程序，研究Z形截面钢筋混凝土柱在双向偏心受压的情况下，弹性范围内的截面变形协调性。通过对不同截面尺寸的Z形截面钢筋混凝土柱进行理论分析，表明Z形截面柱符合平截面假定，其柱截面正应变分布等值线近似为直线。利用自编正截面承载力分析程序，研究了Z形截面钢筋混凝土柱在双向偏心受压的情况下，正截面承载力的变化情况。研究表明，，荷载角、轴压比以及肢端配筋形式等均对正截面承载力有明显影响，纵筋配筋率、纵筋强度和混凝土强度等级的增加都可以在一定程度上提高正截面的承载能力。在对不等肢Z形截面的研究中，根据不同的截面高宽比及肢高厚比确定了截面的最不利荷载角，且研究发现截面的高度和宽度的差值不宜过大否则容易造成截面在不同荷载角情况下极限承载力数值相差过大，出现明显薄弱的受荷角度。通过自编柱截面曲率延性计算程序，分析得到了Z形截面柱截面曲率延性比与多组构件参数之间的内在关系。分析表明荷载角、纵筋的设置和箍筋的设置都能对Z形截面柱曲率延性产生较大影响。混凝土强度与Z形截面柱的截面高宽比两个参数对截面曲率延性影响相对较小。箍筋与纵筋的设置有一定的联动关系，即箍筋间距与纵筋直径的比值越小，越能提高Z形截面柱的延性。根据梁铰破坏机制研究了框架结构的位移延性与异形柱柱截面曲率延性比的关系，得出不同抗震等级下异形柱所需的曲率延性比值。利用自编程序对25920种工况下的Z形截面柱进行非线性分析，得到了与配箍特征值相关的轴压比限值。
[Abstract]:Concrete special-shaped column frame structure is widely used in architectural design because of its superiority in building layout. However, as one of the basic sections of special-shaped columns, Z-shaped columns are not reflected in special-shaped columns. In this study, the normal section bearing capacity and section ductility of Z section column are analyzed comprehensively by using self-compiled program and ANSYS large finite element program. The research includes material characteristics. The influence of many factors, such as section size and loading mode, on the bearing capacity and ductility of columns. In this paper, the deformation compatibility of Z section reinforced concrete columns under biaxial eccentricity is studied by ANSYS program. Through the theoretical analysis of the reinforced concrete columns with different section sizes, it is shown that the Z section columns conform to the assumption of plane section, and the isoline of the normal strain distribution of the columns is approximately straight line. The variation of normal section bearing capacity of Z section reinforced concrete columns under biaxial eccentric compression is studied by using self-compiled program for normal section bearing capacity analysis. The results show that the load angle, axial compression ratio and the reinforcement form at the end of the limb have obvious influence on the bearing capacity of the normal section. The reinforcement ratio of the longitudinal reinforcement, the strength of the longitudinal reinforcement and the strength grade of the concrete can all increase the bearing capacity of the normal section to a certain extent. In the study of Z section of unequal limb, the most unfavorable load angle of section is determined according to different aspect ratio and height to thickness ratio. It is found that the difference between the height and width of the section should not be too large or it is easy to cause the difference of the ultimate bearing capacity of the section under different load angles. The internal relations between the curvature ductility ratio of Z section columns and the parameters of multiple components are analyzed by using a self-compiled program for calculating the curvature ductility of columns. The analysis shows that the load angle, the setting of longitudinal reinforcement and the setting of stirrups can greatly affect the curvature ductility of Z section columns. The ratio of concrete strength to section height to width of Z section column has little effect on the ductility of section curvature. There is a certain linkage between stirrups and longitudinal bars, that is, the smaller the ratio of stirrups spacing to the diameter of longitudinal bars, the more the ductility of Z-section columns can be improved. According to the failure mechanism of beam hinge, the relation between displacement ductility of frame structure and curvature ductility ratio of special-shaped column section is studied, and the ratio of curvature ductility required by special-shaped column under different seismic grade is obtained. In this paper, the nonlinear analysis of Z section columns under 25920 working conditions is carried out by using a self-programmed program, and the limit values of axial compression ratio related to the eigenvalues of the hoop are obtained.
【学位授予单位】：天津大学
【学位级别】：博士
【学位授予年份】：2013
【分类号】：TU375.3

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