本文選題：箱梁 + 有限單元法��； 參考：《重慶大學(xué)》2014年碩士論文

【摘要】：梁橋是橋梁結(jié)構(gòu)中的一種古老的結(jié)構(gòu)體系，在已有的大跨預(yù)應(yīng)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(shí)，就會(huì)產(chǎn)生相應(yīng)的內(nèi)外約束應(yīng)力，即所謂的溫差應(yīng)力。當(dāng)應(yīng)力較大時(shí)，因其帶來(lái)的變形與裂縫問(wèn)題將對(duì)橋梁結(jié)構(gòu)的安全構(gòu)成威脅。本文以貴廣線幸福源水庫(kù)雙線特大橋?yàn)楣こ瘫尘�，�?duì)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(chǎng)和溫度效應(yīng)進(jìn)行了分析研究。 論文的主要研究工作如下： ①對(duì)背景橋梁橫截面的溫度場(chǎng)進(jìn)行了現(xiàn)場(chǎng)實(shí)測(cè)。介紹了箱梁溫度場(chǎng)的測(cè)試方案；對(duì)箱梁在日照升溫、日落降溫以及寒潮降溫作用下的實(shí)測(cè)數(shù)據(jù)進(jìn)行了詳細(xì)的分析；總結(jié)了箱梁在各因素下溫度場(chǎng)隨時(shí)間的變化規(guī)律；為溫度場(chǎng)的有限元仿真分析提供了寶貴的實(shí)測(cè)數(shù)據(jù)。 ②介紹了計(jì)算溫度場(chǎng)和溫度應(yīng)力的有限元理論。介紹了熱傳導(dǎo)的基本理論，，包括傅立葉熱傳導(dǎo)微分方程和求解方程的定解條件；在變分原理的基礎(chǔ)上，介紹了計(jì)算不穩(wěn)定溫度場(chǎng)的有限單元法；通過(guò)空間溫度應(yīng)力問(wèn)題的基本方程的建立，介紹了求解彈性溫度應(yīng)力問(wèn)題的有限元法。為箱梁溫度場(chǎng)和溫度應(yīng)力的分析奠定了理論基礎(chǔ)。 ③利用ANSYS有限元軟件進(jìn)行了溫度場(chǎng)和溫度效應(yīng)的數(shù)值模擬。根據(jù)第一類邊界條件，利用實(shí)測(cè)數(shù)據(jù)建立了二維有限元模型，對(duì)箱梁在日照升溫、日落降溫以及寒潮降溫作用下的溫度場(chǎng)進(jìn)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(chǔ)的參數(shù)化批處理命令流，對(duì)比了數(shù)值分析結(jié)果與現(xiàn)場(chǎng)實(shí)測(cè)結(jié)果，驗(yàn)證了數(shù)值分析的準(zhǔn)確性和可靠性；通過(guò)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(chǎng)計(jì)算結(jié)果與擬合曲線，對(duì)箱梁在日照作用下的橫向溫度應(yīng)力和縱向溫度應(yīng)力進(jìn)行了分析。 ④對(duì)箱梁在驟然降溫作用下的溫度效應(yīng)進(jìn)行了分析。通過(guò)引入寒潮強(qiáng)度，構(gòu)造了四種不同寒潮強(qiáng)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(guò)改變寒潮強(qiáng)度相關(guān)參數(shù)，對(duì)不同工況下的溫度效應(yīng)進(jìn)行了定量對(duì)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(xué)位授予單位】：重慶大學(xué)
【學(xué)位級(jí)別】：碩士
【學(xué)位授予年份】：2014
【分類號(hào)】：U441.5

【參考文獻(xiàn)】

相關(guān)期刊論文 前6條

1 張子明;石端學(xué);倪志強(qiáng);;寒潮襲擊時(shí)的溫度應(yīng)力及簡(jiǎn)化計(jì)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(yīng)力[J];水利學(xué)報(bào);1964年01期

3 崔飛,袁萬(wàn)城,史家鈞;傳感器優(yōu)化布設(shè)在橋梁健康監(jiān)測(cè)中的應(yīng)用[J];同濟(jì)大學(xué)學(xué)報(bào)(自然科學(xué)版);1999年02期

4 張建榮;劉照球;;混凝土對(duì)流換熱系數(shù)的風(fēng)洞實(shí)驗(yàn)研究[J];土木工程學(xué)報(bào);2006年09期

5 王效通;;預(yù)應(yīng)力混凝土箱梁溫度場(chǎng)計(jì)算的有限元法[J];西南交通大學(xué)學(xué)報(bào);1985年03期

6 魏光坪;;單室預(yù)應(yīng)力混凝土箱梁溫度場(chǎng)及溫度應(yīng)力研究[J];西南交通大學(xué)學(xué)報(bào);1989年04期

相關(guān)博士學(xué)位論文 前2條

1 徐豐;混凝土箱梁橋溫度效應(yīng)關(guān)鍵因素研究[D];華中科技大學(xué);2009年

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

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