半刚性节点圆柱面巨型网格结构力学性能研究

发布时间：2019-05-18 21:55

【摘要】：从严格意义上讲，空间结构中应用的节点连接大多是介于完全刚接和理想铰接的半刚性节点。目前，对半刚性节点常规网壳的研究，国内外已经获得了一些成果，而对于巨型网格结构这种国内新兴的空间大跨结构，，目前的研究主要集中在力学性能、计算方法、优化分析和抗震研究等方面，而且在这些研究中均把节点连接作为铰接处理，没有考虑到实际节点连接的半刚性。本文从节点刚度入手，研究半刚性节点圆柱面巨型网格结构的力学性能。以Ansys有限元分析软件为工具，建立了半刚性节点圆柱面巨型网格结构数值模型，并验证了模型的正确性；分别研究了不同数量级节点轴向刚度和弯曲刚度对结构静力稳定性的影响，并推测两者叠加的影响效应可能更大；于是借鉴了已有的焊接球节点刚度本构模型，考虑两者的叠加效应，提出了适合该本构模型的不断逼近计算方法；选用了本结构适合的焊接球规格，引入节点半刚性，分别计算了结构满跨均布荷载和活荷半跨均布情况下的静力稳定承载力；根据极限荷载状态下的杆件内力分布情况，得到了结构的破坏条件；对焊接球半刚性节点结构进行了静力分析；最后分析了焊接球半刚性节点结构和不同数量级轴向半刚性节点结构的自振特性和地震响应。结果表明：随着节点轴向刚度数量级的增大，结构静力稳定承载力显著提高，弯曲刚度影响甚微，两者的叠加效应显著；静力条件下，大多数情况结构破坏由强度条件控制，结构设计时应考虑材料的弹塑性；静力计算时，随着焊接球半刚性节点刚度的减小，结构的弦杆内力显著增大，设计时不能忽略；本结构适合的焊接球节点刚度变化范围对结构的自振特性和动力响应影响很小，可以忽略；不同数量级节点轴向刚度对结构的动力分析影响显著。
[Abstract]:Strictly speaking, most of the node connections used in spatial structure are semi-rigid joints between complete rigid connection and ideal hinged joint. At present, some achievements have been made in the research of conventional reticulated shells of semi-rigid joints at home and abroad, but for mega-grid structure, which is a new spatial long-span structure in China, the current research mainly focuses on mechanical properties and calculation methods. Optimization analysis and seismic research, and in these studies, the joint connection is treated as the joint, and the semi-rigidity of the actual joint connection is not taken into account. In this paper, the mechanical properties of semi-rigid joint cylindrical mega-grid structure are studied from the point of view of joint stiffness. Using Ansys finite element analysis software as a tool, the numerical model of semi-rigid joint cylindrical mega-grid structure is established, and the correctness of the model is verified. The effects of axial stiffness and bending stiffness of different orders of magnitude on the static stability of the structure are studied respectively, and it is inferred that the superposition of the two may have a greater effect on the static stability of the structure. Therefore, the existing stiffness constitutive model of welded ball joint is used for reference, and the continuous approximate calculation method suitable for the constitutive model is put forward considering the superposition effect of the two models. The suitable welding ball specification of the structure is selected, and the static stability bearing capacity of the structure under the condition of uniform load with full span and uniform load with half span is calculated respectively. According to the internal force distribution of the bar under ultimate load, the failure conditions of the structure are obtained, and the static analysis of the welded ball semi-rigid joint structure is carried out. Finally, the natural vibration characteristics and seismic response of welded ball semi-rigid joint structure and different number of axial semi-rigid joint structures are analyzed. The results show that with the increase of the axial stiffness of the joint, the static stability bearing capacity of the structure increases significantly, and the bending stiffness has little effect, and the superposition effect of the two is significant. Under the static condition, the structural failure is controlled by the strength condition in most cases, and the elastoplasticity of the material should be considered in the structural design. In the static calculation, with the decrease of the stiffness of the welded ball semi-rigid joint, the internal force of the chord of the structure increases significantly, which can not be ignored in the design. The suitable stiffness range of welded ball joints has little effect on the natural vibration characteristics and dynamic response of the structure, and the axial stiffness of different orders of magnitude has a significant effect on the dynamic analysis of the structure.
【学位授予单位】：西安建筑科技大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TU399;TU311.3

【相似文献】