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  本文關(guān)鍵詞： 有限元模型修正 荷載試驗 測試數(shù)據(jù) 目標函數(shù)　出處：《重慶交通大學(xué)》2015年碩士論文　論文類型：學(xué)位論文

【摘要】：隨著我國公路與鐵路等基礎(chǔ)建設(shè)的開展,我國橋梁規(guī)模與數(shù)量越來越大。不論是新建的橋梁還是在役橋梁,它們的承載能力總是受到橋梁研究者以及相關(guān)部門的關(guān)注。成橋荷載試驗與加固后橋梁的荷載試驗是檢測橋梁承載力的有效手段。然而,荷載試驗時間比較長,且需要封閉交通,對道路暢通造成不利影響。根據(jù)圖紙設(shè)計參數(shù)建立的有限元模型是荷載試驗布載方案制定以及測試數(shù)據(jù)對比的重要參照,有限元模型的計算值與荷載試驗的測試值存在比較大的差異。本文通過研究有限元模型的修正方法,構(gòu)造不同的目標函數(shù),在ANSYS有限元平臺,通過一個工字鋼簡支梁的數(shù)值算例,通過人為對其相關(guān)參數(shù)的折減造成數(shù)值模型的損傷,求出損傷后有限元模型的特定結(jié)點的位移值以及頻率作為測試值,通過測試值構(gòu)造不同目標函數(shù),對比分析基于靜力單目標函數(shù)、基于動力單目標函數(shù)以及聯(lián)合靜動力目標函數(shù)對模型修正效果,通過此數(shù)值算例,驗證此有限元模型修正方法的正確性。后續(xù)章節(jié)以寂靜特大橋荷載試驗為工程背景,用荷載試驗測試值構(gòu)造上述目標函數(shù),分別對有限元模型中主梁與橋墩的相關(guān)參數(shù)進行修正,修正后的有限元模型計算值與測試數(shù)據(jù)之間的誤差有明顯的減小,與測試數(shù)據(jù)較之修正前更加吻合,修正后的模型更能體現(xiàn)實橋的靜動力特征。本文結(jié)尾探究了大跨度柔性懸索橋青草背長江大橋有限元模型修正方法,以荷載試驗中工況下主梁測點撓度測試數(shù)據(jù)構(gòu)造目標函數(shù),對青草背長江大橋有限元模型中主梁的彈性模量和抗彎慣性矩以及截面面積、主纜的等效彈模修正,然后以有限元模型主梁撓度計算值與測試數(shù)據(jù)對比,評價基于主梁測點撓度測試值構(gòu)造的單目標函數(shù)的修正方法。經(jīng)過數(shù)值算例與實橋?qū)τ邢拊Ｐ托拚椒ǖ尿炞C,說明修正后的模型比按照圖紙設(shè)計參數(shù)建立的有限元模型分析結(jié)果更接近荷載試驗測試數(shù)據(jù),更能反映橋梁的實際狀況,修正后的模型可以為橋梁服役期的養(yǎng)護運營提供參考,可通過修正后的有限元模型對該橋進行荷載承載力評定。
[Abstract]:With the development of highway and railway infrastructure in China, the scale and number of bridges in our country are becoming larger and larger. Their bearing capacity is always concerned by bridge researchers and relevant departments. Bridge load test and strengthened bridge load test is an effective means to detect the bearing capacity of bridge. However, the load test time is relatively long. The finite element model established according to the drawing design parameters is an important reference for the formulation of load distribution scheme and the comparison of test data. There is a big difference between the calculated value of finite element model and the test value of load test. In this paper, by studying the modification method of finite element model, different objective functions are constructed. Through a numerical example of a simply supported I-beam, the damage of the numerical model is caused by the reduction of the relevant parameters, and the displacement value and frequency of the finite element model after the damage are calculated as the test values. Different objective functions are constructed by test values, and the effect of model correction based on static single objective function, dynamic single objective function and combined static and dynamic objective function is compared and analyzed. The validity of the finite element model modification method is verified. In the following chapters, the above objective function is constructed by using the load test results of the Silent Super large Bridge as the engineering background. The relative parameters of the main beam and pier in the finite element model are revised respectively. The error between the calculated value of the modified finite element model and the test data is obviously reduced, which is more consistent with the test data than before. The modified model can better reflect the static and dynamic characteristics of the real bridge. At the end of this paper, the finite element model correction method of the Qingcao-back Yangtze River Bridge with long span flexible suspension bridge is explored. The objective function is constructed from the deflection test data of the main beam measured points under the load test conditions. The elastic modulus, bending moment of inertia and cross-section area of the main girder and equivalent elastic modulus of the main cable in the finite element model of the Qingcaobei Yangtze River Bridge are revised, and then the calculated values of the deflection of the main girder of the finite element model are compared with the test data. The correction method of single objective function based on deflection test value of main beam measuring point is evaluated, and the finite element model modification method is verified by numerical example and real bridge. It shows that the modified model is closer to the test data of load test than the finite element model established according to the parameters of drawing design, and it can reflect the actual condition of the bridge, and the modified model can provide reference for the maintenance and operation of the bridge service period. The load bearing capacity of the bridge can be evaluated by the modified finite element model.
【學(xué)位授予單位】：重慶交通大學(xué)
【學(xué)位級別】：碩士
【學(xué)位授予年份】：2015
【分類號】：U446

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本文編號：1512373