本文關(guān)鍵詞： 正交異性鋼橋面板 殘余應(yīng)力 溫度場(chǎng) 應(yīng)力場(chǎng) 焊接 數(shù)值模擬　出處：《西南交通大學(xué)》2015年碩士論文　論文類型：學(xué)位論文

【摘要】：正交異性鋼橋面板由于各方面具有的獨(dú)特優(yōu)勢(shì),于現(xiàn)代橋梁建設(shè)中得到越來(lái)越廣泛地認(rèn)可與使用。然而隨著服役時(shí)間的增加,許多橋面板上已經(jīng)涌現(xiàn)出不同程度的疲勞問(wèn)題,對(duì)結(jié)構(gòu)的使用性和安全性造成了非常嚴(yán)重的影響。正交異性鋼橋面板結(jié)構(gòu)復(fù)雜,縱肋、橫肋等焊接到橋面板上,焊接所產(chǎn)生的殘余應(yīng)力以及應(yīng)力集中對(duì)疲勞強(qiáng)度有著極為不利的影響。本文針對(duì)此特殊構(gòu)造,模擬其焊接加工過(guò)程并計(jì)算焊后殘余應(yīng)力值,得出該結(jié)構(gòu)殘余應(yīng)力整體分布情況,重點(diǎn)關(guān)注極易出現(xiàn)裂紋處的焊接殘余應(yīng)力分布狀況。論文主要工作如下：首先,介紹了正交異性鋼橋面板及其由焊接引發(fā)的疲勞問(wèn)題,再分別概括了焊接殘余應(yīng)力的定義、分類、產(chǎn)生的原因和對(duì)結(jié)構(gòu)的影響,總結(jié)歸納了有哪些實(shí)驗(yàn)測(cè)試方法以及簡(jiǎn)要敘述了它的消除方式,并結(jié)合實(shí)驗(yàn)所用測(cè)試方法以及殘余應(yīng)力消除措施做了進(jìn)一步說(shuō)明。其次,有針對(duì)性地論述了有限元分析理論在焊接中的應(yīng)用及其特點(diǎn),并總結(jié)了有限元模擬焊接過(guò)程涉及的關(guān)鍵技術(shù)。列出了焊接熱過(guò)程中傳熱基本形式、有限元方法分析的基本方程,進(jìn)一步闡述了對(duì)于涉及非線性瞬態(tài)問(wèn)題時(shí),分析所用離散方法。同時(shí),簡(jiǎn)要說(shuō)明了在有限元分析焊接應(yīng)力場(chǎng)時(shí)所用基本理論與準(zhǔn)則。然后,對(duì)基于ANSYS軟件的熱分析方法進(jìn)行概述。詳細(xì)總結(jié)了模擬焊接溫度場(chǎng)、應(yīng)力場(chǎng)的步驟及方法,其中待解決的關(guān)鍵問(wèn)題有：模型的建立、網(wǎng)格的劃分、單元的選擇、熱源的選擇、邊界條件的確定、荷載的施加、溫度場(chǎng)與應(yīng)力場(chǎng)之間的耦合、模擬熱源的移動(dòng)、焊縫逐步成形的關(guān)鍵技術(shù)以及荷載步的確定。最后,依據(jù)上述理論研究并參照實(shí)驗(yàn)?zāi)Ｐ徒⒂?jì)算模型。確立采用三維有限元數(shù)值方法模擬其溫度場(chǎng)及應(yīng)力場(chǎng),針對(duì)問(wèn)題選取形狀規(guī)則的無(wú)中間節(jié)點(diǎn)的六面體實(shí)體單元以及一定溫度范圍內(nèi)的材料熱物理參數(shù),合理規(guī)劃網(wǎng)格劃分密度,邊界條件選擇室溫且結(jié)合實(shí)際情況確定采用雙橢球熱源模型,并對(duì)熱源參數(shù)的選取進(jìn)行評(píng)定,采用參數(shù)化設(shè)計(jì)語(yǔ)言編寫程序?qū)崿F(xiàn)熱源移動(dòng)；應(yīng)力場(chǎng)計(jì)算時(shí),施加邊界條件限制剛體位移并讀入計(jì)算所得的溫度荷載,再利用生死單元法模擬焊縫的逐步填充。首先計(jì)算得到U肋焊于橋面板的溫度場(chǎng)和應(yīng)力場(chǎng)分布；在此基礎(chǔ)上拼裝橫隔板,繼而研究?jī)煞N不同橫隔板構(gòu)造下各自殘余應(yīng)力分布狀況,主要對(duì)兩種結(jié)果進(jìn)行對(duì)比分析,綜合評(píng)判哪種構(gòu)造細(xì)節(jié)應(yīng)力分布對(duì)結(jié)構(gòu)整體疲勞強(qiáng)度更為有利；再對(duì)加焊橫隔板前后U肋焊縫殘余應(yīng)力分布變化做了簡(jiǎn)單分析；最后用實(shí)驗(yàn)所測(cè)數(shù)據(jù)對(duì)計(jì)算結(jié)果進(jìn)行校核驗(yàn)證計(jì)算值的可靠性,為優(yōu)化焊接結(jié)構(gòu)、選擇更合理的焊接形式提供重要依據(jù)。同時(shí),本文數(shù)值模擬所得的殘余應(yīng)力大小和分布情況為今后評(píng)價(jià)結(jié)構(gòu)的疲勞強(qiáng)度做好了鋪墊。
[Abstract]:Due to the unique advantages of orthotropic steel bridge panels, they are more and more widely recognized and used in modern bridge construction. However, with the increase of service time, fatigue problems of various degrees have emerged on many deck panels. The structure of orthotropic steel bridge is complicated, longitudinal rib and transverse rib are welded to the deck of the bridge. The residual stress and stress concentration produced by welding have a very adverse effect on the fatigue strength. In this paper, the welding process of the structure is simulated and the residual stress value after welding is calculated, and the overall distribution of residual stress in the structure is obtained. The main work of this paper is as follows: firstly, this paper introduces orthotropic steel bridge face and fatigue caused by welding, and then generalizes the definition of welding residual stress. Classification, causes and effects on structures, summarizes and summarizes the experimental test methods and briefly describes its elimination methods, and further explains the test methods and residual stress relief measures used in the experiments. In this paper, the application and characteristics of finite element analysis theory in welding are discussed, and the key technologies involved in simulating welding process by finite element method are summarized. The basic forms of heat transfer in welding heat process and the basic equations of finite element method analysis are listed. The discrete method used in the analysis of nonlinear transient problems is further expounded. At the same time, the basic theory and criteria used in finite element analysis of welding stress field are briefly explained. The method of thermal analysis based on ANSYS software is summarized. The steps and methods of simulating welding temperature field and stress field are summarized in detail. The key problems to be solved are the establishment of model, the division of grid, the selection of element, the selection of heat source, and so on. The determination of boundary condition, the application of load, the coupling of temperature field and stress field, the movement of simulated heat source, the key technology of weld forming step by step and the determination of load step. According to the above theoretical research and referring to the experimental model, the calculation model is established. The three-dimensional finite element numerical method is used to simulate the temperature field and stress field. In order to solve the problem, the hexahedron solid element without intermediate node and the material thermophysical parameters in a certain temperature range are selected, and the density of mesh is reasonably planned. The boundary conditions are chosen at room temperature and combined with the actual conditions. The double ellipsoid heat source model is adopted, and the selection of the heat source parameters is evaluated. The program is written by parametric design language to realize the heat source movement. When the stress field is calculated, The boundary condition is applied to limit the rigid body displacement and read the calculated temperature load. Then the progressive filling of the weld is simulated by the birth and death element method. Firstly, the distribution of temperature field and stress field of the U-rib welding on the bridge slab is calculated. On this basis, the transverse diaphragm is assembled, and then the distribution of residual stress under two different structures is studied, and the two results are compared and analyzed. The variation of residual stress distribution of U-ribbed weld before and after welding is analyzed simply by synthetically judging which structural detail stress distribution is more favorable to the overall fatigue strength of the structure. Finally, the reliability of the calculated results is verified by the experimental data, which provides an important basis for optimizing the welding structure and selecting a more reasonable welding form. The magnitude and distribution of residual stress obtained by numerical simulation in this paper provide a good basis for evaluating the fatigue strength of structures in the future.
【學(xué)位授予單位】：西南交通大學(xué)
【學(xué)位級(jí)別】：碩士
【學(xué)位授予年份】：2015
【分類號(hào)】：U441.4;U445.7

【參考文獻(xiàn)】

相關(guān)期刊論文 前10條

1 李晉梅;雷毅;;用數(shù)值模擬方法研究焊接工藝參數(shù)對(duì)熔池幾何形狀的影響[J];電焊機(jī);2008年05期

2 張初冬;;焊接熱場(chǎng)的三維有限元分析[J];大連鐵道學(xué)院學(xué)報(bào);1992年03期

3 張行霖;;正交異性鋼橋面板的計(jì)算分析[J];城市道橋與防洪;2012年08期

4 倪強(qiáng),王乘,黃玉盈,張標(biāo)標(biāo);焊接過(guò)程的耦合三維熱彈塑性有限元分析[J];華中理工大學(xué)學(xué)報(bào);1997年01期

5 周張義;李芾;;焊接殘余應(yīng)力對(duì)鋼結(jié)構(gòu)疲勞性能影響研究[J];機(jī)車電傳動(dòng);2009年02期

6 曾春華;;殘余應(yīng)力對(duì)疲勞的影響[J];機(jī)械強(qiáng)度;1984年03期

7 陳錫棟;楊婕;趙曉棟;范細(xì)秋;;有限元法的發(fā)展現(xiàn)狀及應(yīng)用[J];中國(guó)制造業(yè)信息化;2010年11期

8 羅利偉;付小超;;焊接殘余應(yīng)力的產(chǎn)生及其消除方法[J];山西建筑;2008年20期

9 汪建華,陸?zhàn)?村川英一;AN FEM MODEL OF BUCKLING DISTORTION DURING WELDING OF THIN PLATE[J];Journal of Shanghai Jiaotong University;1999年02期

10 趙佃龍;方興;白玲;;正交異性鋼橋面板構(gòu)造細(xì)節(jié)改進(jìn)的探討[J];鐵道建筑;2011年02期

相關(guān)博士學(xué)位論文 前1條

1 賈栗;工字鋼—端板組焊結(jié)構(gòu)焊接殘余應(yīng)力有限元分析[D];山東大學(xué);2013年

，

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