格构式钢管混凝土风电塔架万向包裹式空间节点力学分析与性能设计

Previous studies showed that the lattice concrete-filled steel tubular wind turbine tower has many advantages, such as providing better wind conditions, good reliability, low cost, disassembly convenience, high utilization rate of the material and no subject to restrictions on transport conditions ,but its higher machining accuracy and complex spatial stress state has become the bottleneck of model tower engineering application. In view of this, the project proposed an universal package node. The plane and spatial lattice tower were tested subjected to horizontal reversal force, which are made by lattice concrete-filled steel tubular columns connected steel web member with the new spatial nodes. The contest research the failure mechanism and the main influencing factors and quantitative indexes of performance control of the spatial nodes. And establishing the computational model of nodes. According to the connection of the ductility of nodes and the associated members, we analyze restricting mechanism between the node failure mode and failure modes of web-members, and get the stiffness ratio limit of component consisting of nodes, evaluated that feasibility and effectiveness of the application of new spatial node to the lattice concrete-filled steel tubular wind turbine tower system. The nodes required strength is computed and the links between ductility and bearing capacity are established. The new spatial node design methods are put forward. The effective use of structural measures of node energy consumption is proposed. The optimization energy consume organization of composed node element come trued. The results will help us to get a useful supplement to the current relevant norms of the node.

研究表明格构式钢管混凝土风电塔架具有可提供更好风况、可靠性好、造价低、拆装便利、材料利用率高、不受运输条件限制等诸多优点，但其节点较高的加工组装精度和复杂的空间耦合受力状态成为新型塔架工程应用的瓶颈。鉴于此，本项目提出了万向包裹式空间节点，针对由新型空间节点、格构式钢管混凝土塔柱和腹杆组成的平面及空间塔架，进行低周反复荷载试验。研究空间节点的破坏机理、性能控制的主要影响因素及量化指标，建立节点的计算模型。将节点延性和各关联构件延性联系起来，分析节点破坏模式与构件破坏模式之间的影响和制约关系，得到节点各关联构件的刚度比限值。对新型空间节点在格构式钢管混凝土风电塔架体系中应用的可行性和有效性进行评估。计算节点所需的强度，在延性与承载力之间建立联系，建立新型空间节点设计方法，提出有效利用节点耗能的构造措施，实现节点各关联构件的优化耗能组合。研究成果将使我国现行相关规范的节点部分得到有益的补充。

本项目针对格构式钢管混凝土风电塔架万向包裹式空间节点的力学性能进行研究，评估节点在风电领域使用的可行性和有效性。课题根据风电塔架的工作特点和节点构造要求，设计了多种节点形式，通过理论分析、有限元模拟及试验研究等方法，分析了节点连接性能和节点破坏对风电塔架整体结构反应的影响，在确保达到期望的塔架耗能机构水平下，评估了整个风电塔架结构关联构件性能、富裕强度和延性性能。研究了节点破坏模式发生顺序和发展程度对风电塔架整体耗能能力的影响，提出了控制节点破坏和耗能模式的关键参数，实现了节点各关联构件的优化耗能组合。节点的研究结果表明，螺栓球型节点的破坏模式主要为外包球台的屈曲破坏和球台与包裹体间的焊缝撕裂破坏，球台壁厚和包裹体厚度是节点承载力的关键影响因素。插板式节点的破坏模式分为节点板屈曲破坏、包裹体滑移破坏和球柱剪切破坏，其中节点板厚度的变化对破坏模式的影响最为显著，球柱高度次之。Y型节点的破坏模式全部为腹杆的屈曲破坏，球台高度和壁厚对节点承载力的影响显著。双球节点破坏模式分为球台强度破坏和球台压板屈曲破坏。椭球型节点的破坏模式分为球台承板焊缝破坏、球台压板强度破坏以及高强螺栓破坏，球台壁厚为主要控制因素，腹杆-塔柱刚度比次之。平面塔架的研究结果表明，Y型节点塔架的破坏模式为Y型连接件剪切破坏和腹杆内高强螺栓强度破坏，腹杆与塔柱管径比和壁厚比为主要影响因素。插板式节点塔架的破坏模式主要为球柱强度破坏，斜腹杆屈曲失稳和横腹杆撕裂破坏，腹杆-塔柱刚度比成为控制因素。空间塔架的研究结果表明，四肢柱钢管混凝土球板型节点风电塔架的破坏模式为腹杆屈曲破坏和包裹体滑移破坏，腹杆-塔柱刚度比对塔架的承载力与延性影响较大。.总之，万向包裹式空间节点具有较好的受力性能，优点较多，值得推广应用，但仍有很多内容需要进一步研究。本项目的研究成果可为我国编制具有自主知识产权的相关节点的设计规程和施工标准，提供理论基础和实验依据。