本文關(guān)鍵詞： 鋼管混凝土 拱橋 徐變效應(yīng) 幾何非線性 耦合　出處：《長(zhǎng)沙理工大學(xué)》2014年碩士論文　論文類(lèi)型：學(xué)位論文

【摘要】：鋼管混凝土作為一種組合材料其核心混凝土處于三向受壓狀態(tài),材料抗壓強(qiáng)度和抗變形能力得到了增強(qiáng),憑借著材料的穩(wěn)定可靠性及便于安裝生產(chǎn)等優(yōu)越性,鋼管混凝土拱橋正在朝著大跨徑乃至超大跨徑的趨勢(shì)發(fā)展。由于核心混凝土密閉于鋼管內(nèi),因此鋼管混凝土材料的徐變與普通混凝土不同。鋼管對(duì)內(nèi)部密閉的混凝土起著約束的作用,同時(shí)混凝土也制約著鋼管,在徐變的影響下,兩者之間會(huì)發(fā)生應(yīng)力重分布的現(xiàn)象,隨著時(shí)間的增加,鋼管應(yīng)力會(huì)呈明顯上升的趨勢(shì)而混凝土應(yīng)力則會(huì)相應(yīng)降低。本文在敘述了徐變產(chǎn)生原理及其認(rèn)識(shí)的基礎(chǔ)上,比較分析了目前國(guó)內(nèi)外常用的幾類(lèi)徐變模式,并介紹了徐變計(jì)算的基本原理和方法,對(duì)比分析了徐變產(chǎn)生過(guò)程中的各項(xiàng)影響因素,然后以某中承式鋼管混凝土系桿拱橋?yàn)楣こ瘫尘?利用ANSYS通用有限元軟件實(shí)現(xiàn)了對(duì)其主拱肋模型的徐變效應(yīng)分析。結(jié)構(gòu)計(jì)算中,多采用線性理論,隨著鋼管混凝土拱橋跨徑日益加大,其幾何非線性特點(diǎn)也日趨明顯。本文在闡述幾何非線性的基本計(jì)算方法及其理論的基礎(chǔ)上,利用ANSYS對(duì)某鋼管混凝土拱橋有限元模型進(jìn)行了考慮幾何非線性影響下與線性影響的對(duì)比計(jì)算分析。對(duì)于同時(shí)考慮幾何非線性及徐變耦合作用影響的研究目前還較少見(jiàn),本文在采用微分法導(dǎo)出了平面梁?jiǎn)卧獛缀畏蔷�性切線剛度矩陣的基礎(chǔ)上,結(jié)合徐變效應(yīng)計(jì)算的初應(yīng)變法,利用FORTRAN語(yǔ)言編制了同時(shí)考慮幾何非線性及徐變耦合分析程序,并使用該程序進(jìn)行了某橋塔懸臂梁模型的算例分析驗(yàn)證。
[Abstract]:Concrete-filled steel tubular (CFST) as a composite material its core concrete is in a three-direction compression state the compressive strength and deformation resistance of the material has been enhanced by virtue of the material stability reliability and ease of installation and production and other advantages. Concrete-filled steel tubular arch bridge is developing towards the trend of long span and even large span, because the core concrete is confined to the steel tube. Therefore, the creep of concrete-filled steel tube is different from that of ordinary concrete. The steel tube plays a restraint role on the inner confined concrete, and the concrete also restricts the steel tube, under the influence of creep. Stress redistribution will occur between the two, with the increase of time. The stress of steel pipe will increase obviously and the stress of concrete will decrease accordingly. Based on the description of the principle and understanding of creep, several kinds of creep modes commonly used at home and abroad are compared and analyzed in this paper. The basic principle and method of creep calculation are introduced, and the influencing factors in the process of creep are compared and analyzed. Then, a through concrete filled steel tubular tied arch bridge is taken as the engineering background. The creep effect of the main arch rib model is analyzed by using ANSYS software. The linear theory is used in the structure calculation, and the span of concrete-filled steel tube arch bridge is increasing day by day. The characteristics of geometric nonlinearity are becoming more and more obvious. In this paper, the basic calculation method of geometric nonlinearity and its theory are expounded. The finite element model of a concrete-filled steel tubular arch bridge is analyzed by using ANSYS. The effects of geometric nonlinearity and creep coupling are considered in this paper. It's rare at the moment. Based on the derivation of geometric nonlinear tangent stiffness matrix of plane beam element by differential method, the initial strain method is used to calculate creep effect. A program for coupled analysis of geometric nonlinearity and creep is developed by using FORTRAN language, and an example of a cantilever beam model of a bridge tower is given.
【學(xué)位授予單位】：長(zhǎng)沙理工大學(xué)
【學(xué)位級(jí)別】：碩士
【學(xué)位授予年份】：2014
【分類(lèi)號(hào)】：U441;U448.22
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本文編號(hào)：1448816