【作者】 陈烜；

【导师】 王铁成；

【作者基本信息】 天津大学 ， 结构工程， 2013， 博士

【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。更多还原

【Abstract】 The special-shaped concrete column frame structure has plenty of advantages inarchitectural design, and hereby is widely adopted in civil architecture design.However, as one of the basic sectional forms for special-shaped column components,the Z-shaped cross-section is not fully explicated in existing industrial norms. For thisreason, a self-compiled program and the ANSYS large-scale finite element programare utilized in this paper to fully analyze the normal section bearing capacity andductility of the Z-shaped cross-section column. This research is designed to studymultiple factors’ influence on the bearing capacity and ductility of column section,including material characteristics, sectional dimension, and loading conditions.Detailed tasks include:In the paper, the ANSYS large-scale finite element program is applied to study thecoordination of sectional deformation within elastic range, under the circumstancethat the Z-shaped reinforced concrete cross-section column is bearing eccentricpressure from two directions. According to the theoretical analysis on the Z-shapedcross-section reinforced concrete columns of different sectional dimensions, theZ-shaped cross-section reinforced concrete column is proved to comply with theassumption of plane cross-section, and its positive strain distribution level curve isapproximately a straight line.A self-compiled normal section bearing capacity analysis program is adopted to studythe changes of normal section bearing capacity when the eccentric pressure comesfrom two different directions. It is shown that load angle, axial compression ratio, andreinforcement form have significant influence on normal section’s bearing capacity.The improvement of vertical reinforcement ratio, longitudinal bar strength or concretestrength grade enhances the bearing capacity of normal section to some extent. Inresearches specialized on Z-shaped cross-sections of unequal limb lengths, the mostadverse load angle of cross-section is calculated according to concrete sectionalheight-width ratio and limb height-thickness ratio. Furthermore, it is shown that thedifference between sectional height and width is not suggested to be over large. Onthe other hand, values of sectional bearing capacity may become largely different,giving rise to obviously weak loading angles.Taking advantage of the self-compiled column section curvature ductility computingprogram, the inherent relation between Z-shaped section column curvature ductilityratio and multiple component parameters is analyzed and acquired as well.Furthermore, it is found that, load angle, longitudinal bar configuration, and stirrupconfiguration call have a significant influence on the curvature ductility of theZ-shaped cross-section column. On the contrary, the two parameters of concretestrength and the sectional height-width radio of the Z-shaped cross-section columncreate relatively lower influence on the curvature ductility of cross-section. Accordingto further analysis, configuration of stirrup and longitudinal bar has a certain linkedrelationship, i.e. smaller ratio between stirrup spacing and longitudinal bar diameterleads to higher ductility of the Z-shaped cross-section column.According to the beam-hinge failure mechanism, the relationship between framestructure’s displacement ductility and special-shaped cross-section column’s curvature ductility is further analyzed in this paper. The ratio of curvature ductility forspecial-shaped column under different classes of seismic measure is calculated as well.On this basis, the self-compiled program is applied to nonlinearly analyze theZ-shaped cross-section column under25920kinds of working conditions, as well asto figure out the limit value of axial compression ratio correlated with stirrupcharacteristic value.更多还原