稳定型悬索桥成形优化分析

发布时间：2018-10-04 19:49

【摘要】：稳定型悬索桥以普通悬索桥为基本形式,在桥下方增加反向倒张结构(含倒张索和拉杆)。从而使桥梁成为预张结构。桥梁被相对进行了“固化”,刚度也得到很大提高。然而不同载荷和作用位置时会出现以下现象：(1)由于桥的受载后局部变形明显的效应,倒拉杆会出现放松现象,轴力减小明显,甚至出现零拉力或压力的情形。这样当活载上桥后,倒拉杆有可能变为零杆,降低了预张的作用,悬索桥整体的稳定性受到影响；(2)因初始设计张拉方式及桥的受载局部性,倒杆的杆力受力不均,差异较大。有的倒杆拉力过大,影响使用寿命及安全性,而有的倒杆拉力过小,不起什么作用。悬索桥整体刚度受到影响；(3)由于桥是预张结构,受载后任何一个构件受力发生改变都会引起各构件应力的重新分配,张拉状态发生改变。因此需要寻找一种既能保证桥载荷转移功能的实现确保桥的刚度又能使各构件受力合理的张拉状态。这就需要对稳定性悬索桥张拉方案进行优化,找到较优的张拉方案。针对以上问题,本文主要研究内容及成果： (1)系统梳理与阐述了用于稳定型悬索桥的非线性有限元理论,掌握了相关的Fortran程序。 (2)根据稳定型悬索桥预张结构中构件受力状态改变影响整体分布特性的状况,提出了通过调整倒拉杆长度、并在各种载荷工况下进行验证,再行调整的张拉优化准则及优化方案。 (3)应用稳定型悬索桥索、杆、梁的组合结构有限元计算程序,按设计的优化方案对某稳定型悬索桥的结构成形进行了优化计算。对比分析了优化前后的桥形态,倒杆受力,主缆、倒缆受力,吊杆拉力等。总结了倒索的合理张拉线型。研究结果显示优化方法是正确的,优化达到了预期,为桥设计提供参考。 (4)将智能控制方法引入稳定型悬索桥力学性能维持控制中。制定了维持桥力学性能的智能化控制系统的实施方案,在大量计算对比基础上提出了维持桥性能的应变准则。对作动器,控制器,传感器等进行了选择,形成智能控制系统。
[Abstract]:The stable suspension bridge takes the ordinary suspension bridge as the basic form and adds the reverse inverted tension structure (including the inverted tension cable and the pull rod) to the bottom of the bridge. Thus the bridge becomes pretensioned structure. The bridge was relatively "solidified" and its stiffness was greatly improved. However, the following phenomena will occur at different loads and action positions: (1) due to the obvious local deformation effect after the bridge is loaded, the reverse pull rod will be relaxed, the axial force will decrease obviously, and even the situation of zero tension or pressure will occur. Thus, when the live load is mounted on the bridge, the inverted tension bar may become zero bar, which reduces the pretension effect, and the overall stability of the suspension bridge is affected. (2) because of the initial design tension mode and the bearing locality of the bridge, the force of the inverted rod is uneven and the difference is great. Some reverse rod tension is too large, affecting service life and safety, while some reverse rod tension is too small to play a role. The whole stiffness of suspension bridge is affected. (3) because the bridge is a pretension structure, the stress of each member will be redistributed and the tension state will be changed when any member is subjected to load. Therefore, it is necessary to find a kind of tension state which can not only guarantee the load transfer function of the bridge, but also ensure the stiffness of the bridge and the force of each member. Therefore, it is necessary to optimize the tensioning scheme of the stable suspension bridge and find a better tensioning scheme. In view of the above problems, the main contents and achievements of this paper are as follows: (1) the nonlinear finite element theory for stable suspension bridges is systematically combed and expounded, and the relevant Fortran program is mastered. (2) according to the condition that the change of the stress state of the members in the pretension structure of the stable suspension bridge affects the overall distribution characteristics, it is put forward that the length of the inverted tension rod is adjusted and verified under various load conditions. To adjust the tensioning optimization criteria and optimization scheme. (3) based on the finite element program of cable, bar and beam of stable suspension bridge, the structural forming of a stable suspension bridge is optimized according to the design optimization scheme. The shape of the bridge before and after optimization, the force of the inverted rod, the force of the main cable, the force of the inverted cable and the tension of the suspender are compared and analyzed. The reasonable tension line of the inverted cable is summarized. The results show that the optimization method is correct and the optimization meets the expectations, which provides a reference for bridge design. (4) the intelligent control method is introduced into the mechanical performance maintenance control of the stable suspension bridge. The implementation scheme of intelligent control system for maintaining the mechanical properties of the bridge is established, and the strain criterion for maintaining the performance of the bridge is put forward on the basis of a large number of calculations and comparisons. The actuators, controllers and sensors are selected to form an intelligent control system.
【学位授予单位】：昆明理工大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：U448.25

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