弦支穹顶结构施工控制理论与温度效应研究

发布时间：2018-05-29 14:31

本文选题：弦支穹顶 + 施工支承架　；参考：《天津大学》2011年博士论文

【摘要】：弦支穹顶是一种高效的预应力空间钢结构,已推广用于体育馆、会展中心等近20项大跨度建筑工程中。随着工程应用的推广和研究的深入,在施工控制技术与分析设计理论方面遇到了一些亟待解决的关键课题,包括弦支穹顶结构临时支承结构的分析设计理论、考虑温度变化和滑移摩擦影响的弦支穹顶的预应力施工过程数值模拟与控制理论、太阳辐射作用下弦支穹顶结构温度荷载的数值模拟理论及其温度效应研究等,这些课题解决的好坏,直接影响到弦支穹顶的结构效能、工程造价及施工阶段和使用阶段的安全等问题。本文围绕上述问题,采用数值分析与试验研究相结合的方法,开展了系统深入的分析研究,取得了一些具有科学意义和工程应用价值的研究成果。弦支穹顶施工时通常会采用扣件式钢管满堂支承架作为结构和施工荷载的临时支承,而目前扣件式钢管满堂支承架半刚性分析计算理论尚不完善,由此带来了很多问题,甚至工程事故。结合行业标准《扣件式钢管脚手架安全技术规范》(JGJ 130-2001)修订工作,通过足尺试验和理论分析对扣件式钢管满堂支承架的结构力学特点、分析方法及其设计理论进行了深入的研究,提出了一套完整的扣件式钢管满堂支承架的数值模拟理论和简化计算方法,揭示了各个参数对结构稳定性能的影响规律,相关研究成果已编入行业标准《扣件式钢管脚手架安全技术规范》(JGJ 130-2011)。在弦支穹顶结构预应力张拉施工过程中,环索与撑杆下节点之间的滑移摩擦引起显著的预应力张拉偏差,给结构带来了一定的安全隐患。为系统深入的研究滑移摩擦导致的预应力偏差及其对结构性能的影响,本文基于拉索的热胀冷缩原理及其泛函广义逆的概念,考虑滑移摩擦建立了环索绕撑杆下节点滑移的数值模拟理论,通过ANSYS的APDL语言编程实现;同时基于有限元基础理论,推导了基于有限元列式的三节点滑移索单元和闭合多滑轮滑移索单元的刚度矩阵、质量矩阵,通过商用有限元软件ABAQUS的用户自定义单元功能,将单元算法用于计算机手段进行实现索滑移的数值模拟。通过算例和试验验证上述三种索滑移数值模拟理论的合理性。利用上述理论,分别研究了滑移摩擦导致的预应力偏差的分布规律、偏差对弦支穹顶结构性能的影响、环索滑移与不滑移时结构性能的对比分析等内容,得出了一些可供工程参考的结论。在弦支穹顶结构预应力施工期间,环境温度与结构温度是不断变化的,并且变化的幅度较大,给结构的预应力张拉的精确施工带来技术难题。本文首先通过算例分析得出由预应力张拉期间环境温度变化引起显著的预应力张拉误差,误差可达212%,因此必须考虑环境温度的变化对预应力施工的影响。为考虑施工期间环境温度的变化对预应力施工的影响,本文提出了循环补偿法和简化线性方法来考虑施工过程中环境温度变化对预应力张拉施工的影响,通过算例对方法的合理性和精度进行了验证。在弦支穹顶结构的施工阶段和使用阶段,其结构本身的温度场是一个不断变化的过程。温度作用作为一种特殊的荷载,与重力荷载、风荷载、地震作用等常规荷载有着本质的不同,后者可通过增强结构的刚度来有效抵抗,但是前者却不然,刚度越大,温度作用引起的内力就越大,因此对于温度作用引起的内力不能仅靠增加结构的刚度来抵抗。本文采用有限元理论研究了温度作用对弦支穹顶的预应力大小、节点位移、杆件内力和支座反力的影响,揭示了拉索材料和支座约束刚度对温度作用下弦支穹顶结构性能的影响规律。在弦支穹顶结构的施工阶段和使用阶段,其结构温度场不仅受到环境空气温度的影响,而且还受到太阳辐射的影响,太阳辐射作用下,结构表面的温度可超出环境空气温度20℃之上,若设计和施工过程中不能合理的考虑结构的温度场,将会引起安全隐患。本文基于有限元理论,建立太阳辐射作用下钢结构温度场数值模拟方法,并提出了一种高效的太阳阴影计算方法。采用本文建立的数值模拟和阴影计算方法采用ASHRAE晴空辐射模型,建立了太阳辐射作用下钢结构的温度场分析模型,研究了钢板太阳辐射吸收系数、地面辐射反射系数、构件规格和空间方位对结构温度场的影响,完成了钢板、钢管、箱型钢管和H型钢四组太阳辐射下钢构件的温度场试验,验证了理论分析模型和简化计算方法的有效性和合理性。利用本文提出的太阳辐射下钢结构温度场数值模拟方法,研究了太阳辐射下弦支穹顶和弦支穹顶叠合拱结构的温度场分布规律,并揭示了此温度场下弦支穹顶的结构响应规律。
[Abstract]:The chord dome is a kind of high efficient prestressed space steel structure, which has been popularized in the gymnasium, exhibition center and other 20 long-span construction projects. With the popularization and research of the engineering application, some key problems which need to be solved in the construction control technology and the theory of analysis and design are encountered, including the temporary support of the stringed dome structure. The numerical simulation and control theory of the prestressed construction process of the chord dome under the influence of temperature change and sliding friction, the numerical simulation theory of the temperature load of the chord dome structure under the action of solar radiation and the study of the temperature effect on the chord dome structure under the effect of solar radiation, and so on, which directly affect the knot of the chord dome. Structure efficiency, construction cost and construction stage and safety of use stage. This paper, based on the above problems, adopts the method of combining numerical analysis with experimental research to carry out systematic in-depth analysis and research, and has obtained some research achievements with scientific significance and engineering application value.
In the construction of the stringed dome, the full support frame of the fastener type steel tube is usually used as the temporary support for the structure and the construction load. At present, the theory of the semi rigid analysis and calculation of the full support frame of the fastener type steel pipe is not yet perfect, so many problems, even the engineering accidents, are brought up, and the safety technical specification of the fastener type steel tube scaffold > (J GJ 130-2001) revise work. Through full scale test and theoretical analysis, the structural mechanics characteristics, analysis method and design theory of the full support frame of the fastener type steel pipe are deeply studied. A complete set of numerical simulation theory and simplified calculation method of the full fastener type steel pipe full support frame is put forward, and the structure stability of each parameter is revealed. The relevant research results have been incorporated into the industry standard < Safety Specification for fastener style steel pipe scaffolds > > (JGJ 130-2011).
In the process of prestressed tension construction of the stringed dome structure, the slip friction between the ring and the bracing rod causes significant prestress tension deviation, which brings a certain safety hidden danger to the structure. It is based on the thermal expansion and cold contraction of the cable in this paper to study the prestress deviation and its influence on the structure performance. The principle and the concept of the functional generalized inverse are considered, and the sliding friction is considered to establish the numerical simulation theory of the slip of the node under the ring wound pole, and is realized by the APDL language programming of ANSYS. At the same time, based on the finite element theory, the stiffness matrix of the three node slip cable element and the closed multi pulley slip cable element based on the finite element method is derived, and the mass of the slip cable element is derived. By using the user defined unit function of the commercial finite element software ABAQUS, the element algorithm is used to simulate the numerical simulation of the slip of the cable. The rationality of the three kinds of cable slip numerical simulation theory is verified by an example and experiment. The influence of the distribution law and deviation on the structural properties of the chord dome, the comparison and analysis of the structural properties of the ring cable slip and the non slip structure are given, and some conclusions can be obtained for the engineering reference.
During the prestressed construction of the stringed dome, the temperature of the environment and the structure temperature are constantly changing, and the amplitude of the change is large, which brings the technical difficulties to the precise construction of the prestressed tensioning structure. It is up to 212%, so it is necessary to consider the influence of the change of ambient temperature on the prestress construction. In order to consider the influence of the change of the ambient temperature on the prestress construction during the construction period, this paper proposes the cyclic compensation method and the simplified linear method to consider the influence of the environmental temperature change on the pre stress tensioning construction during the construction process. The rationality and accuracy are verified.
The temperature field of the structure itself is a changing process in the construction and use stages of the stringed dome. As a special load, the temperature action is essentially different from the conventional loads, such as gravity load, wind load, and earthquake action, and the latter can be effectively resisted by the stiffness of the strengthening structure, but the former is not. The greater the stiffness, the greater the internal force caused by the temperature action, so the internal force caused by the temperature action can not be resisted only by increasing the stiffness of the structure. In this paper, the effect of temperature action on the size of the prestress, the displacement of the joint, the internal force of the rod and the counterforce of the support are studied by the finite element theory, and the material and support of the cable are revealed. The influence of beam stiffness on the performance of suspended dome structure under temperature.
The structure temperature field is not only influenced by ambient air temperature, but also influenced by the solar radiation. Under the action of solar radiation, the temperature of the structure surface can exceed the ambient air temperature of 20 degrees C. If the temperature field of the structure can not be considered reasonably in the design and application process, the temperature field of the structure will not be considered reasonably. This paper, based on the finite element theory, establishes a numerical simulation method for the temperature field of steel structure under the action of solar radiation, and puts forward a high efficient calculation method of the sun shadow. By using the numerical simulation and shadow calculation method established in this paper, the ASHRAE clear air radiation model is used to establish the temperature of the steel structure under the action of the solar radiation. The effect of the solar radiation absorption coefficient, the ground radiant reflection coefficient, the component specification and the spatial orientation on the temperature field of the structure is studied by the field analysis model. The temperature field test of four groups of steel members under the solar radiation of steel plate, steel tube, box type steel tube and H type steel is completed. The validity and rationality of the theoretical analysis model and the simplified calculation method are verified. By using the numerical simulation method of the temperature field of steel structure under the solar radiation, the temperature field distribution law of the laminated arch structure under the chord dome and the chord dome under the solar radiation is studied, and the structural response law of the lower chord dome at this temperature field is revealed.
【学位授予单位】：天津大学
【学位级别】：博士
【学位授予年份】：2011
【分类号】：TU399

【引证文献】