基于改进的模拟植物生长算法的弦支穹顶结构优化设计研究及其抗震性能分析

发布时间：2018-08-06 19:59

【摘要】：弦支穹顶结构是由上部网壳和下部张拉索杆体系组合而成,是一种具有自平衡性的新型杂交预应力空间结构体系。其整体稳定性能较好,对边界约束要求较低,施工难度相对较小,且造型美观、新颖,具有广阔的应用前景。本文在总结已有研究成果的基础上,对弦支穹顶结构的优化设计和抗震性能进行了研究,以期进一步推进该结构体系的发展与应用。在简要回顾弦支穹顶的概念提出、结构特点和工程应用的基础上,总结了该结构的研究现状及其存在问题,阐述了基于模拟植物生长算法的弦支穹顶优化设计研究以及大跨椭圆形弦支穹顶抗震性能分析的理论与实践意义。首次将模拟植物生长算法的基本思想引入土木工程领域。对该算法的理论进行了研究,并结合该算法的搜索全局最优解方式和小概率事件原理,提出了新的算法改进策略——基于概率的生长空间缩聚法,在保证精度的前提下,以期减少算法运行时间,并提高搜索效率。根据改进的模拟植物生长算法的特点,给出了优化算法流程,并采用ANSYS二次开发语言APDL及MATLAB编制了优化设计程序,通过两个算例进行了验证分析,结果表明：基于改进的模拟植物生长算法的结构用钢量优化设计的效果显著,相比遗传算法、二级优化法、相对差商法和连续变量法等,该算法的优化效果具有较为明显的优势。对弦支穹顶及类似的杂交预应力空间结构体系的优化设计特点和难点进行了剖析,并自行编制了优化设计程序,进行基于改进的模拟植物生长算法的弦支穹顶用钢量优化设计,优化结果进一步验证了该算法的可行性和有效性。对大跨椭圆形弦支穹顶结构的抗震性能进行了较为系统的研究。一方面,对弦支穹顶进行模态分析和地震作用下的时程分析,研究了自振频率和振型的规律,分析并对比了弦支穹顶与相应的单层网壳在地震作用及外部荷载下的结构变形和构件内力等特性；另一方面,通过参数影响分析(如：矢跨比、平面形状系数、上部刚性层结构的刚度、环向索预应力值、撑杆长度、拉索及撑杆面积等),较全面地考察了大跨椭圆形弦支穹顶结构的抗震性能,获得了相关规律性的结论,为类似结构体系的设计提供了参考依据。
[Abstract]:The structure of the chord dome is composed of the upper reticulated shell and the lower tension cable rod system. It is a new type of hybrid prestressed space structure system with self balance. Its overall stability performance is better, the requirements for the boundary constraints are low, the construction difficulty is relatively small, and the modeling is beautiful, novel, and has a broad application prospect. This paper has been summed up in this paper. On the basis of the research results, the optimization design and seismic performance of the suspended dome structure are studied in order to further promote the development and application of the structure system.
On the basis of a brief review of the concept, structural features and engineering applications of the chord dome, the research status and existing problems of the structure are summarized, and the theoretical and practical significance of the study on the optimization design of the chord dome based on the simulated plant growth algorithm and the seismic analysis of the large span oval stringed dome is expounded.
The basic idea of simulated plant growth algorithm is introduced to the field of civil engineering for the first time. The theory of this algorithm is studied, and a new algorithm improvement strategy, based on the probability based spatial condensation method, is proposed by combining the global optimal solution of the algorithm and the principle of small probability events. The algorithm runs time and improves the search efficiency.
According to the characteristics of the improved simulation plant growth algorithm, the optimization algorithm flow is given, and the optimized design program is compiled with the ANSYS two development language APDL and MATLAB. The results are verified by two examples. The results show that the improved simulation plant growth algorithm has a significant effect on the steel quantity optimization design. Pass algorithm, two level optimization method, relative difference quotient method and continuous variable method and so on, the optimization effect of the algorithm has obvious advantages.
The optimization design characteristics and difficulties of the chord dome and the similar hybrid prestressed spatial structure system are analyzed, and the optimization design program is compiled by ourselves. The optimization design of the steel quantity for the string dome based on the improved simulation plant growth algorithm is carried out. The optimization results verify the feasibility and effectiveness of the algorithm.
The seismic performance of the large span oval stringed dome structure is systematically studied. On the one hand, the modal analysis and time history analysis of the chord dome are carried out. The laws of the frequency and mode of the vibration are studied, and the structural changes of the chord dome and the corresponding single layer reticulated shell under the earthquake action and external load are analyzed and compared. On the other hand, the aseismic performance of the large span oval stringed dome structure is thoroughly investigated by the parameter influence analysis (such as the vector span ratio, the plane shape coefficient, the stiffness of the upper rigid layer structure, the prestress of the ring cable, the length of the bracing rod, the area of the pull cable and the pole area, etc.). It provides a reference for the design of similar structural system.
【学位授予单位】：华南理工大学
【学位级别】：硕士
【学位授予年份】：2013
【分类号】：TU399;TU352.11

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