本文選題：箱梁 + 有限單元法��； 參考：《重慶大學》2014年碩士論文

【摘要】：梁橋是橋梁結構中的一種古老的結構體系，在已有的大跨預應力混凝土梁橋中，橫截面大多采用了箱形截面。箱梁在日照升溫和驟然降溫作用下的變形受到約束時，就會產(chǎn)生相應的內外約束應力，即所謂的溫差應力。當應力較大時，因其帶來的變形與裂縫問題將對橋梁結構的安全構成威脅。本文以貴廣線幸福源水庫雙線特大橋為工程背景，對其在日照升溫、驟然降溫（包括日落降溫和寒潮降溫）等因素綜合作用下的溫度場和溫度效應進行了分析研究。 論文的主要研究工作如下： ①對背景橋梁橫截面的溫度場進行了現(xiàn)場實測。介紹了箱梁溫度場的測試方案；對箱梁在日照升溫、日落降溫以及寒潮降溫作用下的實測數(shù)據(jù)進行了詳細的分析；總結了箱梁在各因素下溫度場隨時間的變化規(guī)律；為溫度場的有限元仿真分析提供了寶貴的實測數(shù)據(jù)。 ②介紹了計算溫度場和溫度應力的有限元理論。介紹了熱傳導的基本理論，，包括傅立葉熱傳導微分方程和求解方程的定解條件；在變分原理的基礎上，介紹了計算不穩(wěn)定溫度場的有限單元法；通過空間溫度應力問題的基本方程的建立，介紹了求解彈性溫度應力問題的有限元法。為箱梁溫度場和溫度應力的分析奠定了理論基礎。 ③利用ANSYS有限元軟件進行了溫度場和溫度效應的數(shù)值模擬。根據(jù)第一類邊界條件，利用實測數(shù)據(jù)建立了二維有限元模型，對箱梁在日照升溫、日落降溫以及寒潮降溫作用下的溫度場進行了數(shù)值模擬；編制了以第二類和第三類邊界條件為基礎的參數(shù)化批處理命令流，對比了數(shù)值分析結果與現(xiàn)場實測結果，驗證了數(shù)值分析的準確性和可靠性；通過數(shù)據(jù)整理和線性回歸，擬合出了箱梁截面沿梁高和梁寬的溫差變化曲線；建立空間有限元模型，根據(jù)溫度場計算結果與擬合曲線，對箱梁在日照作用下的橫向溫度應力和縱向溫度應力進行了分析。 ④對箱梁在驟然降溫作用下的溫度效應進行了分析。通過引入寒潮強度，構造了四種不同寒潮強度的工況；按第三類邊界條件建立參數(shù)化有限元模型，通過改變寒潮強度相關參數(shù)，對不同工況下的溫度效應進行了定量對比分析。
[Abstract]:Beam bridge is an ancient structure system in bridge structure. In the existing long-span prestressed concrete beam bridge, the box section is mostly used in the cross section. When the deformation of box girder under the action of sunshine and sudden cooling is restrained, the corresponding internal and external restraint stress, that is, the so-called temperature difference stress, will be produced. When the stress is large, the problem of deformation and crack will threaten the safety of bridge structure. In this paper, the temperature field and temperature effect of the double-line bridge of Guangguangliang Xingyuan Reservoir are analyzed and studied under the combined action of sunshine heating, sudden cooling (including sunset cooling and cold wave cooling) and so on. The main research work of this thesis is as follows: 1. The temperature field of the cross section of the background bridge is measured. The measurement scheme of box girder temperature field is introduced, the measured data of box girder under the action of sunshine, sunset and cold wave cooling are analyzed in detail, and the variation law of box girder temperature field with time under various factors is summarized. It provides valuable measured data for finite element simulation analysis of temperature field. 2. The finite element theory of calculating temperature field and temperature stress is introduced. The basic theory of heat conduction is introduced, including Fourier heat conduction differential equation and definite solution condition of solving equation, based on variational principle, finite element method for calculating unstable temperature field is introduced. The finite element method for solving the elastic temperature stress problem is introduced through the establishment of the basic equation of the space temperature stress problem. It lays a theoretical foundation for the analysis of temperature field and thermal stress of box girder. 3 numerical simulation of temperature field and temperature effect is carried out by using ANSYS finite element software. According to the boundary conditions of the first kind, the two-dimensional finite element model is established by using the measured data, and the temperature field of box girder under the action of sunshine, sunset and cold wave is numerically simulated. The parameterized batch command flow based on the second and third boundary conditions is compiled, the accuracy and reliability of the numerical analysis are verified by comparing the numerical analysis results with the field measured results, and the data collation and linear regression are used to verify the accuracy and reliability of the numerical analysis. The temperature difference curve of box girder section along the beam height and width is fitted, and the spatial finite element model is established. According to the temperature field calculation result and fitting curve, the transverse temperature stress and longitudinal temperature stress of box girder under sunlight are analyzed. The temperature effect of box girder under sudden cooling is analyzed. Through the introduction of cold wave intensity, four different cold wave intensity conditions were constructed, and the parameterized finite element model was established according to the third kind of boundary condition, and the temperature effect under different working conditions was compared and analyzed quantitatively by changing the relevant parameters of cold wave intensity.
【學位授予單位】：重慶大學
【學位級別】：碩士
【學位授予年份】：2014
【分類號】：U441.5

【參考文獻】

相關期刊論文 前6條

1 張子明;石端學;倪志強;;寒潮襲擊時的溫度應力及簡化計算[J];紅水河;2006年02期

2 朱伯芳;王同生;丁寶瑛;;重力壩和混凝土澆筑塊的溫度應力[J];水利學報;1964年01期

3 崔飛,袁萬城,史家鈞;傳感器優(yōu)化布設在橋梁健康監(jiān)測中的應用[J];同濟大學學報(自然科學版);1999年02期

4 張建榮;劉照球;;混凝土對流換熱系數(shù)的風洞實驗研究[J];土木工程學報;2006年09期

5 王效通;;預應力混凝土箱梁溫度場計算的有限元法[J];西南交通大學學報;1985年03期

6 魏光坪;;單室預應力混凝土箱梁溫度場及溫度應力研究[J];西南交通大學學報;1989年04期

相關博士學位論文 前2條

1 徐豐;混凝土箱梁橋溫度效應關鍵因素研究[D];華中科技大學;2009年

2 武立群;混凝土箱梁和空心高墩溫度場及溫度效應研究[D];重慶大學;2012年

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