【作者】 刘红军；

【导师】 李正良；

【作者基本信息】 重庆大学 ， 工程力学， 2010， 博士

【摘要】 由于特高压输电塔和大跨越输电塔的塔身较高,这种高柔结构在较大程度上受到各种荷载的控制。相对角钢塔,钢管塔迎风面积小截面回转半径大,因而在我国特高压和大跨越输电线路中被广泛采用。为了施工方便,目前钢管塔节点形式普遍采用插板连接。国内外对受力比较复杂的插板节点研究较少,现有设计理论还不完善,且存在一些不合理性。针对这一现象本文对输电钢管塔插板连接的K型节点的受力性能进行了研究,具体进行了以下几个方面工作:(1)对钢管-插板连接的K型节点进行了足尺试验,探讨了节点在极限状态下的破坏机理。有限元法分析了影响节点承载力的绝对参数和无量纲参数的关系,确定了影响K型节点承载力的主要参数。利用能量法对基于主管控制和环板控制的节点承载力的求解过程进行了推导,得到了估算此类节点承载力的解析模型,该模型考虑了环板和钢管的共同作用,能较准确反映节点局部屈服时塑性铰的发展,简化了节点复杂的受力状态。在试验和有限元分析结果的基础上,提出了两种控制的K型节点极限承载力简化计算公式,为实际工程的设计提供理论依据。(2)通过试验和有限元分析对插板连接的节点板承载力进行了研究,明确了节点板的受力性能和破坏模式;分析了不同破坏模式下宽厚比、无支长度以及节点板构造等主要参数对节点板承载力的影响,在此基础上提出了节点板承载力建议计算公式。节点板中部加肋和十字插板连接改变了节点板失稳的破坏模式及失效路径,大大提高了节点板的承载力。节点板自由边卷边的措施对基于局部屈曲模式的节点板的承载力提高更加有效。(3)对基于负偏心作用的K型节点的承载力进行了试验研究,在此基础上利用有限元分析了不同破坏模式下负偏心对节点承载力的影响。根据等效受力模型分析了在负偏心作用下主管轴力、主管管壁剪力和弯矩三者之间的相互关系并提出了反映三者关系的建议公式。更多还原

【Abstract】 The transmission tower is flexible due to the large height of ultra-high voltage transmission tower and large span tower, thus the internal force is controlled by all load at a certain extend. Compared to the steel angle tower, the steel tubular tower is applied commonly much more because of its smaller windward area, bigger cross-section gyration radius .At present, the tube-gusset joint type is applied mainly owing to the convenience of construction. But there are just a few scholars home and abroad to research the tube-gusset joint which resist complicated force and there are some irrationalities in the theory existence at present. The behavior and strength of tube-gusset joint was explored primarily and the following researches are performed:(1) Full-scale tubular K-joints with tube-gusset plate connections are constructed and tested under static loads.The failure modes and failure mechanism are analyzed.Based on experimentation and FEM , tubular energy theory about the ultimate strength of K-joints was deducted and a limit analysis model for determining the ultimate loads of tube-gusset plate connections is established using ring-generator separation model.In this model, tubular and ribbed-plate were considered and the model reflected the development of the plastic range of K-joints and simplified the performance of mechanics. This paper proposes the calculation method of the ultimate strength of the tube-gusset K-joint under different failure modes.It reveals that the method has theoretical and practical significance for design.(2) The parameters which influence the ultimate strength of gusset-plate and the failure type of the plate was analyzed roundly based on a mass of full size model experiment data and FEM. The failure modes and failure mechanism were analyzed about the plate.The ultimate strength of plate depends on width-thickness ratio, non-limb length and conformation of the plate.The proposal calculation method of the ultimate strength of the plate was put forward based on an inelastic plate buckling equation .The plate was ribbed in the middle part and along splice member,which can alter the failure model and the invalidation avenue and improved the ultimate strength of the plate. Adding free edge stiffeners can increase the buckling strength of gusset-plate connections efficiently.(3) A numerical analysis and experimental study were performed to investigate the behavior and strength of tube-gusset connections subjected to axial and axial brace force. The parameters which influence the ultimate strength of tube-gusset joint and the failure type of joints was analyzed. To suggest a formula for the strength of tube-gusset joint, axial brace forces are replaced by equivalent wall moment and eccentric vertical component force of axial brace force. Non-dimensionalized ultimate strength interaction relations between the wall moment of tube ,vertical axial force ,and eccentric vertical component force of axial brace force were formulated through parametric study.更多还原