大跨度钢结构分段吊装施工过程模拟分析

发布时间：2018-01-19 07:07

本文关键词： 大跨度钢结构施工过程数值模拟分段吊装施工监测　出处：《武汉理工大学》2015年硕士论文　论文类型：学位论文

【摘要】：大跨度钢结构的一系列优点使得这种结构形式发展迅速。由于这种结构形式的复杂性,大跨度钢结构在施工过程中会遇到许多不同的力学问题,结构的内力和位移在施工过程中会发生复杂的变化,如何保证结构在施工过程中的安全可控以及施工完成后的结构能够满足设计的要求,是大跨度钢结构施工过程研究的核心问题。本文以某实验大厅的大跨度钢屋盖结构为项目背景,对其钢桁架的分段吊装进行分析,了解结构在施工过程中的内力和位移的变化情况。本文总结了国内外对大跨度钢结构施工过程的研究成果,简要叙述了大跨度钢结构采用的主要的安装方法以及较为先进的施工方法,施工过程中可能出现的力学问题和主要时变因素,剖析了大跨度钢结构施工过程的计算方法以及利用单元生死技术模拟施工过程的原理和优缺点。本文利用大型通用有限元软件ANSYS进行数值模拟,建立实验大厅的屋盖结构的有限元模型,对结构的原施工方案和修改后的施工方案分别进行施工过程的模拟,研究采用不同施工方法对结构施工过程中安全性的影响,评估改变构件安装次序是否对整个结构有利,并且分析结构下部临时支撑位置不同对结构力学性能的影响。根据模拟计算结果,一次性加载、施工方案一(原施工方案)和施工方案二(部分构件后安装)的结构的竖向位移和最大等效应力均未超过设计要求;通过将两种施工方案与一次性加载的情况进行对比分析,施工方案二的计算结果与一次性加载的情况差别较大,采用施工方案二会使结构在施工完成后具有较大的竖向位移和等效应力,且在桁架端部,即存在杆件后装部位的上弦杆上出现较大的应力;将两种施工方案进行对比可知,采用部分构件后装的施工方法时,结构在施工过程中会长时间处于较大应力的情况,结构的安全储备较低;将同一方案下的两榀桁架进行对比可知,只是临时支撑位置不同的两榀桁架在施工完成后会出现不同的位移和内力情况,临时支撑的位置布置合理会使结构最后的性态更加符合设计要求。本文将计算值与实测值进行对比分析,分析产生误差的原因,为后续桁架的安装提供理论依据和参考性的建议,为保证结构施工过程中的安全以及施工完成后能够达到设计目标,后续桁架的施工尽量不要采用部分构件后装的施工方法,临时支撑也应采用与原施工方案中一致的布置方式。
[Abstract]:Because of the complexity of this kind of structure, the long span steel structure will meet many different mechanical problems in the process of construction. The internal force and displacement of the structure will undergo complex changes in the construction process. How to ensure the safety and control of the structure in the construction process and the structure after the construction can meet the design requirements. It is the core problem in the construction process of long span steel structure. This paper takes the large span steel roof structure of a laboratory hall as the project background and analyzes the steel truss segment hoisting. To understand the internal force and displacement of the structure in the construction process, this paper summarizes the domestic and foreign research results on the construction process of large-span steel structure. This paper briefly describes the main installation methods and advanced construction methods used in long span steel structures, the possible mechanical problems and main time-varying factors in the construction process. This paper analyzes the calculation method of the construction process of the long span steel structure and the principle, advantages and disadvantages of simulating the construction process by using the element birth and death technique. In this paper, the numerical simulation is carried out by using the large-scale universal finite element software ANSYS. The finite element model of the roof structure of the experimental hall is established, and the original construction scheme and the modified construction plan are simulated respectively. This paper studies the effect of different construction methods on the safety of the structure during construction, and evaluates whether changing the installation order of the components is beneficial to the whole structure. The influence of different temporary bracing positions on the mechanical properties of the structure is analyzed. According to the simulation results, the one-off loading is carried out. The vertical displacement and maximum equivalent stress of the structure of construction scheme 1 (original construction scheme) and construction scheme 2 (after installation of some components) do not exceed the design requirements; By comparing the two construction schemes with one-off loading, the calculation results of construction scheme two are quite different from that of one-off loading. The second construction scheme can make the structure have larger vertical displacement and equivalent stress after construction, and the stress will appear in the end of the truss, that is, the upper chord bar in the post of the member. By comparing the two construction schemes, it can be seen that the structure will be in large stress for a long time in the construction process, and the safety reserve of the structure will be low. The comparison of two trusses under the same scheme shows that only two trusses with different temporary bracing positions will have different displacement and internal force after the completion of construction. The reasonable placement of temporary braces will make the final behavior of the structure more in line with the design requirements. In this paper, the calculated value and the measured value are compared and analyzed to analyze the causes of the errors. For the subsequent installation of truss to provide theoretical basis and reference suggestions, in order to ensure the safety of the structure during the construction process and after the completion of the construction can achieve the design objectives. The following truss construction should not adopt the construction method of some members after installation, and the temporary support should also adopt the same arrangement as the original construction plan.
【学位授予单位】：武汉理工大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TU758.11

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