考虑颤振及静力刚度约束的悬索桥优化设计研究

发布时间：2018-05-01 11:19

本文选题：悬索桥 + 颤振分析　；参考：《中南大学》2014年硕士论文

【摘要】：悬索桥是各类桥梁中跨越能力最大的一种桥型。随着跨度的不断增加,悬索桥越来越柔,对风的作用越来越敏感,因而在悬索桥的设计中,抗风问题往往是最重要的控制因素,其中颤振稳定性问题最为突出,必须在初步设计阶段就给予认真考虑和妥善解决。然而,颤振稳定性分析是一个十分复杂的过程,手动调整设计方案以满足颤振稳定性要求只能试算,计算量大且过程繁杂,使设计人员陷入反复计算,无法深入理解气动弹性性能与桥梁设计变量之间的关系。因此引入现代优化设计理论进行自动优化设计显得十分必要且有显著优势。本文在总结前人研究成果的基础上,试图将优化方法运用到悬索桥设计中,使得该桥型方案设计时更加快速、理性,设计成果更优。本文所做主要工作： (1)回顾并总结了悬索桥的结构特点及颤振稳定性分析方法,为优化模型的约束条件计算提供依据。 (2)基于ANSYS,编制了悬索桥全模态颤振频域分析程序,采用黄金分割优化方法进行颤振临界风速搜索,大大提高了计算效率。 (3)基于本文优化问题特点及遗传算法优势,编制了遗传算法FORTRAN程序,并用算例验证了程序的可靠性。 (4)针对悬索桥优化算例,基于APDL语言建立ANSYS空间有限元模型,进行静力分析、模态分析及颤振临界风速搜索,以加劲梁尺寸及主缆尺寸为设计变量,以颤振临界风速及静力挠度为约束条件,以造价最低为目标,根据罚函数思想转换为适应度函数建立了两种优化数学模型。 (5)采用FORTRAN与ANSYS混合编程技术编制了优化总控程序,实现了自动优化计算。 (6)通过实例计算并对优化前后的设计变量、约束条件及目标函数值进行对比,验证了本文优化设计方法的有效性和优化设计变量选择的灵活性。图22幅,表8个,参考文献61篇
[Abstract]:Suspension bridge is one kind of bridge with the largest span capacity among all kinds of bridges. With the increasing span, the suspension bridge becomes more flexible and more sensitive to the wind. Therefore, in the design of the suspension bridge, the wind-resistant problem is often the most important control factor, among which the flutter stability problem is the most prominent. It must be carefully considered and properly resolved at the preliminary design stage. However, flutter stability analysis is a very complex process. Manual adjustment of the design scheme to meet the flutter stability requirements can only be calculated. The relationship between Aeroelastic performance and bridge design variables is not fully understood. Therefore, the introduction of modern optimal design theory for automatic optimization design is very necessary and has significant advantages. On the basis of summarizing the previous research results, this paper attempts to apply the optimization method to the suspension bridge design to make the bridge design faster, more rational and better. The main work of this paper is as follows: 1) the structural characteristics and flutter stability analysis method of suspension bridge are reviewed and summarized, which provides the basis for the calculation of constraint conditions of the optimization model. Based on ANSYS, a full-mode flutter frequency analysis program for suspension bridge is developed. The golden section optimization method is used to search the critical flutter velocity, which greatly improves the calculation efficiency. 3) based on the characteristics of the optimization problem and the advantages of genetic algorithm in this paper, a genetic algorithm (FORTRAN) program is developed, and the reliability of the program is verified by an example. In view of the optimization example of suspension bridge, the finite element model of ANSYS space is established based on APDL language. Static analysis, modal analysis and flutter critical wind speed search are carried out. The dimensions of stiffened beam and main cable are taken as design variables. Taking the critical wind speed and static deflection of flutter as the constraint conditions and taking the lowest cost as the target, two kinds of optimal mathematical models are established according to the idea of penalty function converted into fitness function. 5) the optimization control program is programmed by using the mixed programming technology of FORTRAN and ANSYS, and the automatic optimization calculation is realized. 6) the effectiveness of the optimization design method and the flexibility of the selection of the optimal design variables are verified by comparing the design variables, constraints and objective function values before and after optimization. 22 figures, 8 tables, 61 references
【学位授予单位】：中南大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：U448.25

【参考文献】