本文選題：雙室箱梁　切入點：剪力滯效應(yīng)　出處：《蘭州交通大學(xué)》2014年碩士論文　論文類型：學(xué)位論文

【摘要】：隨著我國經(jīng)濟的發(fā)展，箱梁的使用更加廣泛，，且箱梁的懸臂更加長、翼緣板更加寬。特別是在跨度較大的橋梁的修建中箱梁的使用更加的普遍，在箱梁的逐步發(fā)展和實踐中，設(shè)計人員發(fā)現(xiàn)按初等梁理論計算的結(jié)果已不能滿足結(jié)構(gòu)的實際受力狀態(tài)，經(jīng)研究人員長期研究，發(fā)現(xiàn)由于剪力滯后引起了應(yīng)力的不均勻分布，在工程實踐中發(fā)現(xiàn)諸多由剪力滯引發(fā)的破損現(xiàn)象，引起了研究人員的重視，并且進行了大量的研究和修復(fù)工作，使得箱梁的受力更加符合實際的受力狀態(tài)。本文針對單箱雙室矩形箱梁對不同的加載方式對箱梁剪力滯效應(yīng)的影響進行研究，通過理論和有限元數(shù)值兩種計算方法，對兩種計算的結(jié)果進行比較，并總結(jié)其不同規(guī)律，主要進行了以下幾個方面研究。 在理論計算方面，對單箱雙室矩形箱梁的受力機理進行分析，運用能量變分法原理推導(dǎo)在不同的加載方式作用下雙室箱梁簡支、懸臂兩種邊界條件的箱梁截面的剪力滯系數(shù)表達式和撓度計算公式，在這些公式中有按初等梁理論計算的一部分也有剪力滯影響的附加應(yīng)力和撓度。 在有限元數(shù)值計算方面，本文使用結(jié)構(gòu)計算軟件Midas/FEA，對雙室矩形截面梁進行模擬計算，并將計算結(jié)果與理論計算結(jié)果進行比較，以驗證Midas/FEA軟件計算箱梁正應(yīng)力的準確性。 不同的邊界條件、加載方式對箱梁剪力滯的影響是不同的。選用簡支、懸臂兩種不同的邊界條件，在雙室箱梁上分別施加集中荷載和均布荷載且每種荷載考慮三種荷載工況，用有限元軟件建立不同的邊界條件、加載方式下的結(jié)構(gòu)模型，計算出截面的正應(yīng)力值并且與按初等梁理論計算的結(jié)果相比，所得的結(jié)果就是箱梁剪力滯系數(shù)。對剪力滯系數(shù)進行系統(tǒng)地分析，總結(jié)出不同加載方式對箱梁剪力滯的影響因素，斷面正應(yīng)力的橫向分布規(guī)律，并且可以找出箱梁危險截面的最不利點和最不利的荷載工況，作為結(jié)構(gòu)設(shè)計的控制點。 選取跨度為40m的雙室矩形截面箱梁作為工程背景，采用通用有限元程序MIDAS/FEA建立箱梁橋梁單元有限元模型，分析其在不同荷載作用下簡支、懸臂梁正應(yīng)力的橫向分布規(guī)律和撓度的變化規(guī)律。
[Abstract]:With the development of our country's economy, the use of box girder is more extensive, and the cantilever of box girder is longer, the flange plate is wider, especially in the construction of long-span bridge, the use of box girder is more widespread, and in the gradual development and practice of box girder, The designer found that the calculation results based on the elementary beam theory could not satisfy the actual stress state of the structure. After a long period of research by the researchers, it was found that the stress distribution was uneven due to the shear lag. In engineering practice, many damage phenomena caused by shear lag have been found, which has attracted the attention of researchers, and has carried out a lot of research and restoration work. In this paper, the influence of single box and double chamber rectangular box girder on the shear lag effect of box girder under different loading modes is studied, and the theoretical and finite element methods are used to calculate the shear lag effect of box girder. The results of the two calculations are compared, and their different laws are summarized. In the aspect of theoretical calculation, the stress mechanism of single box and double chamber rectangular box girder is analyzed, and the simple support of double chamber box girder under different loading modes is deduced by using the principle of energy variation method. The shear lag coefficient expression and deflection calculation formula of box girder section under two kinds of cantilever boundary conditions have some additional stresses and deflections affected by shear lag as well as some of them calculated according to elementary beam theory. In the aspect of finite element numerical calculation, the structure calculation software Midas / FEAA is used to simulate the double-chamber rectangular section beam, and the calculated results are compared with the theoretical results to verify the accuracy of the Midas/FEA software in calculating the normal stress of the box girder. The influence of loading mode on shear lag of box girder is different under different boundary conditions. Two different boundary conditions, simple support and cantilever, are applied to double chamber box girder under concentrated load and uniform load respectively, and three load conditions are considered for each load. The finite element software is used to establish different boundary conditions, and the structural model under loading mode is used to calculate the normal stress value of the section and compare with the results calculated according to the elementary beam theory. The result is the shear lag coefficient of box girder. The influence factors of different loading modes on the shear lag of box girder and the transverse distribution of normal stress of section are summarized. The most unfavorable point and the most unfavorable load condition of the dangerous section of the box girder can be found as the control point of the structural design. Taking the double-chamber rectangular section box girder with span of 40 m as the engineering background, the finite element model of the box girder bridge element is established by using the universal finite element program MIDAS/FEA, and the simple support under different loads is analyzed. The transverse distribution of normal stress and the variation of deflection of cantilever beam.
【學(xué)位授予單位】：蘭州交通大學(xué)
【學(xué)位級別】：碩士
【學(xué)位授予年份】：2014
【分類號】：U441;U448.213

【參考文獻】

相關(guān)期刊論文 前6條

1 羅旗幟;變截面箱梁翼緣有效寬度計算[J];公路;1999年07期

2 楊綠峰,高兌現(xiàn),李桂青;箱型梁剪力滯效應(yīng)求解的樣條里茲法[J];廣西大學(xué)學(xué)報(自然科學(xué)版);1998年01期

3 楊綠峰,秦榮,李桂青;廣義參數(shù)有限元法分析箱型梁的剪力滯效應(yīng)[J];貴州工業(yè)大學(xué)學(xué)報;1997年S1期

4 王修信,黃劍源;變截面多跨梯形箱梁橋剪滯效應(yīng)差分解[J];橋梁建設(shè);1993年02期

5 劉自明;橋梁結(jié)構(gòu)模型試驗研究[J];橋梁建設(shè);1999年04期

6 程翔云;懸臂薄壁箱梁的負剪力滯[J];上海力學(xué);1987年02期

本文編號：1618996