带悬臂梁段拼接的梁柱连接节点初始转动刚度研究

发布时间：2018-06-06 20:54

本文选题：带悬臂梁段拼接的梁柱连接 + 高强螺栓　；参考：《华南理工大学》2013年硕士论文

【摘要】：带悬臂梁段拼接的梁柱连接形式是目前在我国多高层钢结构工程中使用较为广泛的一种连接形式。该节点形式在钢结构加工车间里完成悬臂梁段和柱构件的焊接连接工作，而拼接梁段与悬臂梁段之间的连接采用高强螺栓全拼接形式，此部分在工地现场完成。该连接形式克服了施工现场的焊接技术难以保证梁柱连接焊缝质量的缺点，在某种程度上起到了提高施工速度、保证施工质量的作用。但在实际工程的应用过程中依然存在问题，主要集中在两方面：1节点的初始本构关系难以确定；2如何避免梁柱焊缝发生脆性破坏，提高整体的延性。通常情况下，将梁柱之间的全焊缝连接视为刚性连接，假定其在受力过程中具有充分的强度，同时能够保证梁柱间夹角不变。但是大量的实践和研究已经证明这种假定不成立。全焊缝梁柱连接属于半刚性连接，我国颁布的《钢结构设计规范》里明确规定在进行内力分析时，应先确定所采用半刚性连接形式的弯矩-转角特性曲线。更何况对于带悬臂梁段拼接的梁柱连接形式，拼接区的力学性能可能会对梁柱连接处的力学性能产生影响。研究拼接区的主要设计参数对梁柱连接处的初始本构关系的影响程度，比较带悬臂梁段拼接的梁柱连接的初始本构关系与普通全焊接梁柱连接的差别，是本文的任务之一。本文设计制作了2个带悬臂梁段高强螺栓拼接的焊接H型钢梁柱连接节点试件，进行边柱弹性加载、中柱弹性加载和中柱低周反复加载试验，分析试验现象和破坏机理，计算初始刚度。随后运用有限元数值模拟分析，与试验结果进行比较，同时定量分析与普通全焊缝梁柱连接节点形式之间的差别，研究带悬臂梁段拼接的梁柱连接节点初始本构关系的确定方法。另一方面，上个世纪90年代的美国北岭地震和日本阪神地震中，全焊缝梁柱连接发生了大量的脆性破坏，此后大量的研究围绕着如何提高梁柱全焊缝连接节点的延性而展开。研究表明，即使采用更加严格、精细的焊接工艺技术，保证焊缝质量也不足以提高其延性。在塑性受力阶段，依靠焊缝来承受外力，或者说利用焊缝来耗散能量是行不通的。必须对节点形式加以改造，迫使塑性铰从梁柱连接处往外移。为此有学者提出了削弱型节点和增强型节点的概念。带悬臂梁段拼接的梁柱连接形式在梁上存在刚度突变，另外在弹塑性受力阶段，螺栓与拼接板之间、螺杆与孔壁之间会发生滑移，翼缘拼接连接板会发生屈曲，因此可以通过对拼接区合理地设计，，使之在满足承载力要求的前提下，使此类节点的塑性铰在拼接区或其附近产生，可认为是削弱型节点的一种。本文根据目前通用的拼接区设计方法，利用有限元数值建模对主要设计参数进行研究，探求各参数对节点初始刚度和延性的影响程度。最后针对于现有的拼接区设计方法，提出合理地设计建议。
[Abstract]:The Liang Zhu connection with cantilever beam section is widely used in the construction of multi-high-rise steel structures in China at present. The joints are welded to the cantilever beam section and column member in the steel structure processing workshop, and the connection between the cantilever beam segment and the cantilever beam section adopts the full splicing form of high strength bolt, which is completed in the site of the construction site. The joint form overcomes the shortcoming that the welding technology in the construction site is difficult to guarantee the quality of the Liang Zhu joint weld, and to some extent plays the role of improving the construction speed and ensuring the construction quality. However, there are still some problems in the application of practical engineering. It is difficult to determine how to avoid brittle failure of Liang Zhu weld and improve the ductility of the whole by focusing on two aspects of the initial constitutive relation of 1: 1 node. The full weld joint between Liang Zhu is regarded as a rigid connection, which is assumed to have sufficient strength in the process of loading, and the angle between Liang Zhu can be kept unchanged at the same time. But a great deal of practice and research have proved that this assumption is not true. The fully welded Liang Zhu connection is a semi-rigid connection. The Code for Design of Steel structures issued by China clearly stipulates that the bending moment-angle characteristic curve of the semi-rigid connection should be determined first when the internal force is analyzed. Moreover, for the Liang Zhu joints with cantilever beam segments, the mechanical properties of the splicing areas may affect the mechanical properties of the Liang Zhu joints. It is one of the tasks of this paper to study the influence of the main design parameters of the splicing zone on the initial constitutive relation of the Liang Zhu joint, and to compare the difference between the initial constitutive relation of the Liang Zhu connection with cantilever beam splicing and the ordinary fully welded Liang Zhu connection. In this paper, two specimens of welded H-beam Liang Zhu joints with cantilever beam segment high strength bolts are designed and fabricated. The tests of elastic loading of edge column, elastic loading of middle column and repeated low cycle loading of middle column are carried out, and the experimental phenomena and failure mechanism are analyzed. Calculate the initial stiffness. Then the finite element numerical simulation analysis is used to compare the results with the test results, and the difference between the joint form of Liang Zhu joint and that of general weld joint is analyzed quantitatively. In this paper, the method of determining the initial constitutive relationship of Liang Zhu joints with cantilever beam splicing is studied. On the other hand, during the North Ridge earthquake in the 1990s and the Hanshin earthquake in Japan, a large number of brittle failure occurred in the all-weld Liang Zhu connection. Since then, a lot of research has been carried out around how to improve the ductility of Liang Zhu full weld joint. The research shows that the quality of welding seam is not enough to improve its ductility even if more strict and fine welding technology is adopted. In the plastic stress stage, it is impossible to rely on the weld to bear the external force, or to dissipate energy by using the weld. The joint form must be modified to force the plastic hinge to move outward from the Liang Zhu joint. For this reason, some scholars put forward the concepts of weakened node and enhanced node. In addition, in the elastic-plastic stress stage, slippage will occur between bolt and spliced plate, between screw and hole wall, and buckling will occur between flange splice plate. Therefore, the plastic hinge of the joint can be produced in or near the joint area by reasonably designing the splicing zone and making it meet the requirements of bearing capacity, which can be considered as a kind of weakened joint. In this paper, the main design parameters are studied by using finite element numerical modeling according to the common design method of splicing area, and the influence of each parameter on the initial stiffness and ductility of joints is explored. Finally, according to the existing design method of splicing area, the reasonable design suggestion is put forward.
【学位授予单位】：华南理工大学
【学位级别】：硕士
【学位授予年份】：2013
【分类号】：TU973.13

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