本文關鍵詞： 大跨度鋼結構 施工力學 “生死”子結構 預夾角 找形 優(yōu)化　出處：《華南理工大學》2011年博士論文　論文類型：學位論文

【摘要】：施工力學在大跨度鋼結構工程中的應用已經是當今工程界和學術界的熱點課題,該方面研究工作需要對作為其力學基礎的時變力學有清楚的認識和理解。本文在前人工作的基礎上,針對工程界亟待解決的大跨度鋼結構施工相關問題,結合現(xiàn)場監(jiān)測數(shù)據(jù),運用施工力學方法進行了研究,取得了一定的效果。主要工作如下: 1.對施工力學的研究特點及分類進行了分析,完善了土木工程施工力學研究的課題以及施工力學效應。作為研究對象的施工力學理論基礎,重點討論了時變力學主要研究內容以及施工力學基本方法和特點,給出了相應問題的時變力學基本方程和有限元算式。 2.討論了大跨度鋼結構施工力學數(shù)值分析方法、特點和參數(shù)時變的意義,針對施工過程中結構幾何及邊界條件隨時間不斷變化這一施工力學分析難點,基于結構分段安裝以及先裝和后裝可通過節(jié)點構造預夾角的概念,提出“生死”子結構先后獨立求解,調整“死”結構邊界節(jié)點轉動約束條件的施工模擬方法,推導了“生死”子結構的有限元方程。通過典型算例驗證方法的有效性及先進性,并進行了實際工程分析。 3.基于深圳會展中心工程施工和使用期鋼結構的應力和變形現(xiàn)場實測數(shù)據(jù),結合結構主梁、下弦鋼棒以及邊界約束條件時變的特點,進行了全過程“生死單元法”及本文方法的模擬計算和分析。考慮幾何非線性以及胎架的支撐與落架,模擬了多種載荷條件下構件受力和變形,比較分析了三種數(shù)據(jù)及變化規(guī)律;同時進行了拆撐過程路徑相關性分析和探討,得出了一些有益結論,供設計和施工者借鑒。 4.張弦梁找形分析屬于施工力學逆解問題,討論了考慮大變形情況下應用溫降法和初應變法模擬施加預應力時單元剛度和應力產生偏差的問題,提出了相應應力和剛度的修正方法;借鑒機械結構螺栓預緊力的概念,給出了模擬張弦梁預張拉的有效方法并克服了上述方法的弱點,通過典型算例驗證了方法的有效性。 5.鑒于張弦梁張拉過程撐桿轉動對結構體系受力和變形影響大,選擇張拉前后撐桿轉動量極小化為優(yōu)化目標,提出了線性預測-非線性校正的優(yōu)化方法。算例分析了方法的有效性,同時發(fā)現(xiàn)三種拉拔預張拉方式中,從中間跨通過花籃螺栓預張拉相對較好的優(yōu)化結果,對于結構設計和施工具有一定的實際意義。
[Abstract]:The application of construction mechanics in large-span steel structure engineering has become a hot topic in engineering and academic circles. This research work needs to have a clear understanding of time-varying mechanics as the basis of its mechanics. Based on the previous work, this paper aims at the problems related to the construction of long-span steel structures that need to be solved urgently in the engineering field. Combined with the field monitoring data, using the method of construction mechanics to carry on the research, has obtained the certain effect. The main work is as follows: 1. The research characteristics and classification of construction mechanics are analyzed, and the research subject of civil engineering construction mechanics and the effect of construction mechanics are improved, which is the theoretical basis of construction mechanics as the object of study. The main research contents of time-varying mechanics and the basic methods and characteristics of construction mechanics are discussed emphatically. The basic equations of time-varying mechanics and the finite element formulas for the corresponding problems are given. 2. The numerical analysis method of construction mechanics of long span steel structure, its characteristics and the significance of time-varying parameters are discussed. In view of the difficult point of construction mechanics analysis, the geometry and boundary conditions of the structure are constantly changing with time during the construction process. Based on the concept of segmented installation of structure and pre-angle construction of nodes, a construction simulation method of "life and death" substructure is put forward, which adjusts the rotational constraint condition of boundary node of "dead" structure. The finite element equation of "life and death" substructure is derived. The validity and advanced nature of the method are verified by typical examples, and the practical engineering analysis is carried out. 3. Based on the field measured data of stress and deformation of steel structure in construction and service life of Shenzhen Convention and Exhibition Center, combined with the time-varying characteristics of main beam, lower chord steel bar and boundary constraint conditions. The whole process of "birth and death element method" and the method in this paper are simulated and analyzed. Considering the geometric nonlinearity and the support and falling frame of the tire frame, the force and deformation of the member under various load conditions are simulated. Three kinds of data and their changing laws are compared and analyzed. At the same time, the correlation analysis and discussion of the path in the process of brace removal are carried out, and some useful conclusions are obtained, which can be used for reference by designers and constructors. 4. The form-finding analysis of beam string belongs to the inverse solution of construction mechanics. The problem of element stiffness and stress deviation when prestressing is simulated by temperature drop method and initial strain method considering large deformation is discussed. The corresponding stress and stiffness correction method is put forward. Based on the concept of pretension force of bolt in mechanical structure, an effective method for simulating the pretension of beam string is given and the weakness of the above method is overcome. The validity of the method is verified by a typical example. 5. In view of the great influence of the strut rotation on the stress and deformation of the structure system during the tensioning process, the optimum objective is to select the minimum rotation of the strut before and after the tensioning. An optimization method of linear prediction-nonlinear correction is proposed. The effectiveness of the method is analyzed by an example. At the same time, three kinds of drawing pretension methods are found to be relatively good from the middle span through the basket bolt pretension. It has certain practical significance for structural design and construction.
【學位授予單位】：華南理工大學
【學位級別】：博士
【學位授予年份】：2011
【分類號】：TU391

【引證文獻】

相關期刊論文 前1條

1 史曉龍;付永春;;大跨度橋梁施工力學理論及其應用[J];水利建設與管理;2013年04期

相關碩士學位論文 前2條

1 付裕;鋼結構桁架式通廊設計優(yōu)化與工程應用[D];山東大學;2012年

2 陳百會;采用預應力基礎梁的大跨度鋼結構施工控制關鍵技術研究[D];安徽建筑工業(yè)學院;2012年

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本文編號：1470094