交叉支撑体系稳定性分析

发布时间：2018-03-07 14:18

本文选题：稳定　切入点：临界力　出处：《昆明理工大学》2017年硕士论文　论文类型：学位论文

【摘要】：钢支撑除了能大幅提高结构的侧向刚度外,还作为稳定单元提高结构的稳定性。交叉支撑体系是最为常见的钢支撑形式。通常交叉支撑较为细柔,设计时为了简化计算,假设交叉支撑的斜压杆失稳而退出工作,仅考虑斜拉杆受力。正是基于这种假定的设计可能给结构带来风险,因斜压杆失稳时将导致结构出现较大的变形,由此突增的二阶效应可引发结构破坏。因此斜压杆失稳时的临界力应是结构设计时须考虑的一个重要指标。现行规范给出了两杆长度、截面相同且交叉点在杆件中点(标准)的交叉支撑临界力的计算公式,而对于不满足规范假定条件(非标准)的交叉支撑,却未给出相应的计算公式或图表。本论文就以这一现状为背景而展开工作,利用平衡法和二阶位移法推导、建立和求解非标准交叉支撑的临界方程。为能方便工程中快速计算,经几千次的超越方程求解,获得了大量的数据,制成了能求解交叉支撑临界力的(无量纲)诺模图。本论文最有价值的成果就是这些能求解非标准交叉支撑临界力的诺模图(图3.10,图3.19,图4.6和图4.11)。这些诺模图的正确性和可靠性都经过了有限元计算的检验,且计算精度很高。是一快速计算非标准交叉支撑临界力很好的工具,面对《钢结构设计规范》目前还没有该方面的计算表格或公式,也算是一种补充。此外,本论文也在非标准交叉支撑临界力的近似计算方面做了些探索,用挠度法获得了非标准交叉支撑临界力的近似计算公式,如公式(5.6),式(5.7),式(5.8),式(5.9)。这些公式同样用有限元计算进行了检验,计算精度也很高,使用更为方便。
[Abstract]:The steel support in addition to significantly increase the lateral rigidity, but also as a stable unit to improve the stability of the structure. The cross bracing system is the most common form of steel support. Usually cross support is more soft, the design in order to simplify the calculation of inclined pressure bar instability hypothesis cross braced and out of work, only consider the oblique rod by it is designed. This assumption may bring risks based on the structure due to strut instability will lead to large deformation structure, thus the sudden increase in the two order effect can cause structural damage. Therefore the critical force of inclined pressure bar instability should be an important consideration when designing the index structure the current specification is given. Two bar length, and cross section of the same point in the rod midpoint (standard) calculation formula of cross braced for critical force, do not meet the standard assumptions (non standard) cross support, but have not given The formula or chart. This paper is based on this situation as background, using the balance method and two order displacement method is derived, the critical equation and the solution of non standard cross support. In order to fast and convenient calculation in engineering, by solving the transcendental equation for thousands of times, obtained a large amount of data made can solve the cross bracing critical force (dimensionless) nomogram. In this thesis the most valuable is that these results can solve non standard cross support critical force nomogram (Figure 3.10, figure 3.19, figure 4.6 and figure 4.11). The nomogram correctness and reliability are tested through finite element calculation. And the calculating precision is very high. Is a fast calculation of non standard cross support critical force of good tools, in the face of "code for design of steel structures > there is no the calculation form or formula, is a kind of supplement. In addition, this paper also in non standard The approximate calculation made some exploratory forks supporting critical force, obtained the approximate formula for calculating the critical force of non - standard cross braced by deflection method, such as formula (5.6), type (5.7), type (5.8), type (5.9). These formulas are also verified by finite element calculation, calculation precision is also very high, the use is more convenient.

【学位授予单位】：昆明理工大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TU391

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