大跨弦支穹顶环索预应力设计方法及结构优化设计

发布时间：2018-05-27 21:52

本文选题：弦支穹顶结构 + 预应力比　；参考：《广州大学》2017年硕士论文

【摘要】：弦支穹顶是由单层网壳和索-撑体系组合而成的轻度预应力大跨空间结构,其受力性能好、跨越空间距离大、造型优美;目前已广泛用于航站楼、体育场馆、会展中心等大型公共设施屋盖中,如2008年北京奥运会羽毛球馆、济南奥体中心体育馆等屋盖结构均为这种结构体系。弦支穹顶结构设计的核心就是确定最佳环索预应力;过大或过小的环索预应力,都将严重影响结构的受力性能及结构耗钢量等方面。为了确定弦支穹顶结构最优的预应力设计方案,本文选取几何法及撑杆控制面积法确定环索预应力比,选取支座径向位移相等准则及网壳顶点竖向位移相等准则确定环索预应力幅值,将它们进行交叉组合构成4个环索预应力设计方案。另外还选取刚性索法及改进刚性索法作为环索预应力设计方案,共6个预应力设计方案;以2008年北京奥运会羽毛球馆弦支穹顶结构屋盖为研究背景;研究了各个预应力设计方案的优缺点和工程适用性。采用ANSYS优化模块零阶优化方法对弦支穹顶结构进行预应力优化设计。即:以结构总重量为目标函数,考虑构件的长细比、强度应力、稳定应力和结构位移等约束,考虑12个结构设计荷载工况,针对不同的环索预应力设计方案,基于ANSYS-APDL编程语言编制了弦支穹顶结构优化设计程序,充分考虑了预应力与构件截面的相互影响,实现了弦支穹顶结构优化设计过程中环索预应力和构件截面同时优化的目标。为了提高弦支穹顶结构优化设计程度,首次提出改进罚函数优化设计方法,并将改进罚函数优化方法和传统优化方法的优化结果进行综合对比分析;研究表明:改进罚函数优化方法可有效提高了结构的优化程度,以撑杆控制面积法确定环索预应力比,以支座径向位移相等准则确定环索预应力幅值,所获得的结构重量最轻同时结构水平与竖向刚度也最大。为了更深入全面的研究弦支穹顶结构的静力性能,本文详细探讨了包括结构矢跨比、撑杆长度、预应力大小、撑杆面积、环索面积等参数对其静力性能的影响;以期为今后弦支穹顶结构的工程设计和实际应用提供有价值的参考。
[Abstract]:The chord dome is a light prestressed long-span spatial structure composed of single-layer reticulated shell and cable-bracing system. It has good mechanical performance, has a long span of space and has beautiful shape. At present, it has been widely used in terminal buildings, stadiums and stadiums. The roof structure of large public facilities such as Beijing 2008 Olympic Feather Hall and Jinan Olympic Sports Center Gymnasium is this kind of structure system. The core of the design of chord dome structure is to determine the optimum ring cable prestress, which will seriously affect the mechanical performance of the structure and the steel consumption of the structure. In order to determine the optimal prestress design scheme of the dome structure, the geometric method and the bracing control area method are selected to determine the prestressing ratio of the ring cable. The radial displacement equality criterion of support and the vertical displacement equality criterion of the vertex of reticulated shell are selected to determine the prestressing amplitude of ring cable, and four design schemes of ring cable prestress are constructed by cross combination of them. In addition, the rigid cable method and the improved rigid cable method are selected as the design scheme of the ring cable prestressing force, six prestressing design schemes are selected, and the research background is the roof of the domes of the Feather Hall of the Beijing Olympic Games in 2008. The advantages and disadvantages of each prestress design scheme and its engineering applicability are studied. The zero order optimization method of ANSYS optimization module is used to optimize the prestressed design of the dome structure. That is, taking the total weight of the structure as the objective function, considering the constraints of the aspect ratio, the strength stress, the stability stress and the displacement of the structure, 12 structural design load conditions are considered, and different design schemes of the ring cable prestress are considered. Based on the ANSYS-APDL programming language, the optimization design program of the domes structure is developed, which fully considers the interaction between the prestress and the section of the members, and realizes the goal of the optimization of the cable prestress and the section of the members during the optimum design of the domes. In order to improve the degree of optimal design of the dome structure, an improved penalty function optimization method is proposed for the first time, and the optimization results of the improved penalty function optimization method and the traditional optimization method are compared and analyzed synthetically. The study shows that the improved penalty function optimization method can effectively improve the optimization degree of the structure. The ratio of ring cable prestress is determined by the method of bracing control area, and the amplitude of ring cable prestress is determined by the criterion of equal radial displacement of support. The weight of the structure is the lightest and the horizontal and vertical stiffness of the structure is also the largest. In order to study the static performance of the chord dome structure more thoroughly, this paper discusses in detail the influence of the parameters including the rise-span ratio of the structure, the length of the brace, the size of prestress, the area of the brace and the area of the ring cable on the static performance of the dome. In order to provide valuable reference for the engineering design and practical application of the dome structure in the future.
【学位授予单位】：广州大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TU399

【参考文献】