【摘要】：在鋼橋和組合橋設(shè)計時溫度效應(yīng)和疲勞性能都是需要重視的問題。本文從熱傳導(dǎo)基本方程出發(fā),對變熱流作用下的箱梁截面進行全時程分析,計算波紋鋼腹板箱梁橋在不同溫度場下的溫度效應(yīng)；另外采用有限元程序?qū)蛄旱钠谔匦赃M行數(shù)值模擬,研究主要涉及以下幾個方面。 以寧波奉化江大橋為研究背景,采用二維有限元方法分析在7月份橋梁的溫度場變化,分析了在不同時刻典型截面頂板、底板和鋼腹板的外表面、中部和內(nèi)表面溫度變化特點；再輸入數(shù)值模擬的溫度場結(jié)果進行溫度效應(yīng)的分析計算,分析橋梁溫度應(yīng)力的分布特點。將規(guī)范溫度場的溫度效應(yīng)結(jié)果與有限元計算的溫度場導(dǎo)致的效應(yīng)進行分析對比,認為設(shè)計上只考慮頂板溫度應(yīng)力時可以采用規(guī)范T=25℃的溫度場數(shù)據(jù)。 運用MIDAS/FEA建立奉化江大橋波紋鋼箱梁的精細有限元模型,并應(yīng)用英國規(guī)范BS5400和參考文獻提供的數(shù)據(jù)來確定運營階段內(nèi)疲勞車輛的荷載譜,最后根據(jù)經(jīng)典的應(yīng)力-壽命評估方法對該橋運營階段內(nèi)鋼腹板易損點的疲勞壽命進行評估。根據(jù)研究的結(jié)果,在疲勞荷載譜作用下,奉化江大橋鋼腹板各個位置的易損點在100年設(shè)計基準期內(nèi)產(chǎn)生的累計疲勞損傷度均遠小于1。剪力鍵疲勞損傷出現(xiàn)位置為鋼腹板的傾斜面與平直面交界處的鋼筋洞口,但在設(shè)計基準期內(nèi)其不會出現(xiàn)疲勞破壞,所以此橋在設(shè)計的運營階段不會出現(xiàn)相關(guān)的疲勞破壞。
[Abstract]:In the design of steel bridges and composite bridges, the temperature effect and fatigue performance should be paid attention to. In this paper, based on the basic equation of heat conduction, the full time history analysis of box beam section under the action of variable heat flow is carried out, and the temperature effect of corrugated steel webs box girder bridge under different temperature fields is calculated. In addition, the finite element program is used to simulate the fatigue behavior of the bridge. The research mainly involves the following aspects. Taking the Fenghua River Bridge in Ningbo as the research background, the temperature field of the bridge in July was analyzed by two-dimensional finite element method, and the temperature variation characteristics of the outer, middle and inner surfaces of the typical cross-section roof, bottom plate and steel web at different times were analyzed. The temperature effect is analyzed and calculated by inputting the results of numerical simulation, and the distribution characteristics of the temperature stress of the bridge are analyzed. The results of the temperature effect of the gauge temperature field are analyzed and compared with those of the temperature field calculated by finite element method. It is concluded that the temperature field data of 25 鈩，

本文編號：2446488