【作者】 罗葵葵；

【导师】 蒋沧如；

【作者基本信息】 武汉理工大学 ， 结构工程， 2009， 硕士

【摘要】 随着大跨度空间钢结构在大型建筑中越来越广泛的应用,除了在设计理念方面的不断创新,在施工过程中也涌现出大量先进的施工工艺。由于这类结构空间跨度大,造型奇特,结构自身受力复杂;再加上施工过程难度大工期长,施工期间还会受到各种不确定因素的影响。结构施工过程中的受力状态与结构设计状态可能完全不同,如果按传统的结构设计方法进行设计,很难确保结构在施工过程中的安全。因此,有必要针对结构在施工过程中的受力情况进行系统研究,利用仿真模拟的方法分析了结构在施工阶段的力学特性,以保证工程安全、经济、有效的建设完成。在施工过程中所遇到的技术性难题很多,本论文以某抬升裙楼为工程背景,在已有的国内外施工理论研究的基础上,利用有限元软件对抬升裙楼巨型悬挑钢桁架的卸载进行了模拟计算,重点分析了卸载过程中结构内力和位移的变化。论文的主要研究内容如下:(1)鉴于建模需要,对临时支撑胎架进行了设计;(2)利用ANSYS有限元软件,以一简单悬臂梁为例对悬挑结构的卸载进行模拟计算。设定四种卸载方案,对比分别按四种方案卸载时梁在支撑点处弯矩值和支撑反力的变化,分析不同卸载方式和卸载顺序对临时支撑受力及悬挑结构内力的影响,得出较为合理的卸载方式。(3)通过简单模型的模拟计算,综合考虑其它方面因素后,确定采用由内到外分组分步卸载的方式进行卸载。结合大跨度空间悬挑钢桁架结构,对其建立有限元分析模型,分别按照“从内到外”及“从外到内”分组分步卸载的方式对结构实施卸载,然后进行对比分析并得出相关结论。(4)通过上述分析,对该工程悬挑桁架的卸载提供指导性意见,并为其它类似工程提供参考。更多还原

【Abstract】 With the large-span space steel structure used in a large building more and more widely, the design concept is being innovated and also a large number of advanced technologies are emerged in the process of construction. This type of structure with a large span and unusual shape has complex force of its own. Because the construction is very difficult and has a long duration, it will be subject to a variety of uncertain factors during the construction period. The force state is in an absolutely different state between structural design and construction. If the traditional method used for structural design, it is difficult to ensure the structural safety of the construction process. Therefore, it is necessary to carry out systematic research on force state of structure in the construction process and understand the mechanical characteristics of the structure using simulation methods, so that the building can be completed safely, economically and effectively.There are many technical problems in the construction. The research background of this paper is podium uplift with giant cantilevered steel truss. Based on theoretical study at present, the unloading process is simulated by the finite element software to analyze internal forces and displacement changes. The main content of this paper is briefly summarized as follows:(1) Temporary supports are designed as the view of modeling.(2)The unloading of a simple cantilever beam is simulated using of ANSYS according to four unloading program. Compared with the calculation results from support reactions and internal force of trusses, a reasonable unloading program is received.(3)Using simple simulation and considering the other factors, it is decided to adopt the stepped integral synchronous unloading "from inner to outer" and "from outer to inner" to unload supports. Finally, the calculation results are compared and analyzed.(4)By analysis above, it provides the instructive suggestions to the supports unloading and the reference for other similar projects.更多还原