斜交网格结构空间相贯焊接节点承载力分析学位

斜交网格结构空间相贯焊接节点承载力分析

摘要：斜交网格结构是近些年新出现并被应用的新型结构形式，主要应用于高层及超高层建筑和异型建筑，具有外形美观、受力可靠、抗侧刚度大等优点。但现在对斜交网格结构的研究还不是很系统，对斜交节点的研究更是少。由于结构的特殊性，斜交网格结构的节点截面面积小且所受轴力很大，所以节点设计是工程应用中的难点。

这就需要对节点进行特殊设计并辅以电脑设计分析和优化。

本文以大连某观光塔工程为背景，该塔外筒为斜交网格结构，中部收腰，空间构造复杂，空间节点设计具有较大的难度。本文利用大型有限元分析程序进行实体建模，实现对圆钢管斜交网格空间相贯焊接节点进行设计，并进行静力弹性和弹塑性承载力分析。以该塔外筒中某典型节点为例分析了在五种不同的载工况下的加载过程的应力分布情况，得出荷载位移曲线，确定节点在各个工况作用下的设计承载力、屈服承载力、极限承载力等信息，明确节点破坏模式。还分析了节点管、拼接板等各部分的作用及对节点承载力的影响，明确节点的传力模式，分析得出节点主要由管壁和竖向拼接板进行传力，拼接板对节点具有很好的约束作用，对增强节点承载力、节省钢材具有很大的贡献。本文将该节点与相同情况下的铸钢节点进行比较分析，指出两种节点在传力模式，破坏形态及承载力性能都较为相似。

本文将该类斜交节点与现行钢结构规范中的圆管平面X型节点设计承载力计算公式进行比较分析，明确现行规范计算方法不适于该类节点。在规范公式的基础上，本文通过改变多个参数进行比较分析，归纳出适用于在一定范围两种工况时计算该类斜交节点极限承载力及设计承载力的计算公式。

本文重点分析了塔中通透区节点与环梁的相互作用。探索环梁与节点的合理的连接方式，通过对在五种工况下有无连接板、无环梁有连接板、有环梁等节点进行静力弹性和弹塑性承载力对比分析，明确环梁及连接板对节点承载力性能的影响。研究证明，当节点存在较大的平面外弯矩作用时，环梁和连接板在一定程度上提供了一个侧向支撑点，能有效提高节点承载力，且环梁受力较小，连接板的提高作用大于环梁；当节点存在扭转变形时，连接板对节点承载力影响不大，设置环梁对节点有不利影响。

本文将塔中其他节点进行了设计并计算，通过综合分析得出一些结论和建议，可供设计人员做参考研究。

关键词：斜交网格结构；空间相贯焊接节点；承载力；有限元分析

Abstract

Diagonal lattice structure，mainly used in high-rise buildings and shaped，are emerging and applied in recent years. It, beautiful shape, reliable force, large lateral stiffness, is a new structure. However，research on the Diagonal lattice structure are not comprehensive, and less diagonal joints. Generally, the diagonal joints cross-sectional areas are small and suffered a large axial force. This is caused by the special structure. So joints designs are the difficulty of engineering applications. It is necessary to special design and be supplemented by computer for design, analysis and optimization.

This paper the background of a Tower project, Dalian，diagonal lattice structure for the outer tube, central waist and complex spatial structure.So the welded spatial tubular joints is very difficult to design. Load-carrying capacity performance in the static about the welded spatial tubular joints, used in Diagonal lattice Structure, were elastic and elastic-plastic analyzed and designed by finite element analysis program. The stress distributions in the loading process on the welded spatial steel tubular joint used in the tower were analyzed under multiple load cases. Load-displacement curves are obtained. Design load-carrying capacity, yield load-carrying capacity, ultimate load-carrying capacity of such information under multiple load cases are identified also. The role of joints pipe wall and splice plates were analyze and the impact of load-carrying capacity. Comparative analyses of cast steel joints on the performance in the same case are taken.

Comparative analyses with X-uniplanar joint in the existing steel structure design with multiple parameters prove that the code is not suitable for the calculation of such joints. The pape have been summarized in a formula, based on the code, for the ultimate load-carrying capacity and design load-carrying capacity of the welded spatial tubular joints. The paper provides