大型塔器桁架内件结构的设计与计算

桁架具有材料荷载较大的工况利用率高、结构轻巧、利于塔内介质径向流动等优点,在大跨度塔内件支撑中逐渐得到应用;在探讨了形式选择、载荷作用点传到支座端部支撑设置前提下,分析了如何确定塔器支撑用桁架的杆件截面形式、斜杆角度和高跨比;详细介绍了如何进行平面桁架桁架的强度、刚度和稳定性计算,尤其是如何计算梁的最大挠度和长细比;阐述了侧向支撑的设置前提和设置方式,如何进行腹杆与弦杆间的连接节点设计;为了在能够在满足使用要求的前提下尽量减轻桁架的重量,讨论了如何进行桁架进行优化设计,找到最合理的设计序列。

DESIGN AND CALCULATION OF TRUSSED BEAM FOR LARGE TOWER INTERNALS

With advantages of high material utilization rate,compact structure,and good for radial flow of medium in tower,trussed beam is widely used as large span support for tower internals.By discussing the type selection and end support for trussed beam,this article analyzes how to determine the section of truss rod,the angle of diagonal brace and the ratio of height to span,and specifies the calculation of strength,rigidity and stability of trussed beam,especially the maximum deflection and slenderness ratio.After introducing the lateral support and setting method,the design of joints between web member and chord is discussed.In order to reduce the weight of trussed beam while meeting the requirements for use,the optimization design of trussed beam is discussed to find the optimum design sequence.