【作者】 孙文波；

【导师】 梁启智；

【作者基本信息】 华南理工大学 ， 结构工程， 2002， 博士

【摘要】 钢管结构在建筑工程中已经得到了广泛的应用，除了常见的小直径直管被大量地应用于钢网架和网壳结构中，经过弯曲加工的直径较大的钢管作为桁架结构的上下弦杆也越来越多地出现在一些大跨度的钢结构工程中。钢管的弯曲加工工艺方法可大致分为冷弯和热弯两类。其中冷弯加工工艺具有生产效率高、能耗低、生产成本较少等特点，因而具有较为广泛的工程应用背景，但是另一方面，显而易见的事实是钢管经过冷弯加工处理后材料的力学性能也必然发生了较大的变化，而且随着弯曲变形程度的增加，构件力学性能的变化就必然更加剧烈。通常来讲，这种材料性能的改变对于结构和构件的受力性能而言是不利的，如果不考虑这种变化，就会使钢管构件在服役过程中存在不确定的潜在危险，进而成为结构失效和破坏的原因。结合广州国际会议展览中心屋面钢结构工程张弦桁架结构的设计和施工过程的分析和计算，本文对以下三个方面进行了研究和讨论。 1．对于平面圆弧曲杆的近似分析，当杆件的矢高与弦长相比小于大约1／12时，本文提出了一种折线形的等效单元组来模拟圆弧形杆件的刚度性能，并通过算例来初步地验证了这种方法的计算精度。这种方法可以在只增加一个跨中节点的条件下利用直杆有限元程序来近似计算曲杆。 2．对于圆钢管冷热弯成型后钢材性能的变化，本文通过一批不同曲率半径的钢管弯曲试验和材料性能试验来说明它们之间的联系。考虑到弯曲杆件中试验材料取样的困难，有必要通过以弯曲钢管为弦杆的桁架模型试验来加以验证。本文对两榀此类桁架进行了单调静力加载试验，并试图以桁架的宏观刚度来理解弦杆弯曲后的单元刚度的变化情况。 3．通过试验初步确定了钢材材性的变化之后，基于这种变化，并结合曲杆的单元刚度矩阵分析，推导出一种可以考虑材料性能沿杆件横截面以某种规律变化时单元刚度矩阵的计算方法。这种方法同样能与已有程序结合起来使用，应用较为方便。更多还原

【Abstract】 Steel Pipe Structures (SPS) have been widely used in civil engineering. Together with the small-sized steel pipes which have been adopted in steel trusses and lattice shells in a large amount, the curved steel pipes working as chords of trusses are also more and more used in a few large-span steel structures. Because the bending process of steel pipes possesses the special features such as high producing efficiency and low energy consume and less production cost and so on,it can be used in several kinds of structures. On the other hand, it’s obviously that cold-bended steel pipes have their mechanical properties varied greatly. The more the steel pipes are bended, the greatly their properties are changed. Normally, the variety of mechanical properties are harmful to the mechanical characteristic of structure and its members. If this kind of variety is neglected, steel pipes might work in the status of uncertainty and danger. Sometimes it would make the structure failed. Combining with the analysis and calculation of the roof steel structure of Guangzhou International Convention and Exhibition Center, three following parts are studied and discussed.1. With regard to the approximate analysis of arc member,on condition that the ratio of arc’s height to length of chord is limited to about 1/12, a group of piecewise linear curve elements are put forward to imitate the stiffness performance of arc element.With this method,only one additional node should be set up to make use of existing program to calculate arc member approximately.2. With regard to the change of mechanical properties of cold or heat-bended steel pipes, a series of experiments for bended steel pipes and their mechanical properties are carried out to consider the relation更多还原