本文選題：π形斷面　切入點：顫振導數(shù)　出處：《長安大學》2015年碩士論文　論文類型：學位論文

【摘要】：橋梁的風致振動研究中,顫振穩(wěn)定性分析是必不可少的,橋梁顫振是發(fā)散性的自激振動,一旦發(fā)生,會造成毀滅性的災難。顫振導數(shù)是大多數(shù)現(xiàn)有顫振分析方法的核心,是決定顫振臨界風速的關(guān)鍵參數(shù)。本文圍繞π形斷面的顫振導數(shù)主要作了以下工作:首先簡要介紹了橋梁風致效應,并回顧了橋梁顫振穩(wěn)定性研究的發(fā)展歷程和近況;對橋梁斷面顫振導數(shù)的識別理論及方法做出總結(jié)分析,為本文的風洞試驗和數(shù)值模擬提供理論基礎(chǔ);介紹了計算機流體動力學基本理論,分析并確定了適合本文的分狀態(tài)強迫振動算法和數(shù)值模型。然后對帶風嘴的π形主梁斷面分別進行風洞試驗和數(shù)值模擬識別其顫振導數(shù),對比二者結(jié)果,四個主顫振導數(shù)值吻合較好,四個副顫振導數(shù)在個別工況下差異略大,總體來說可用本文的數(shù)值算法識別π形斷面的顫振導數(shù)。通過數(shù)值模擬結(jié)果,分析了風攻角對π形斷面八個顫振導數(shù)的影響。最后,提出了π形斷面的尺寸系數(shù)φ,定義φ為π形斷面寬度B與兩腿間距L的比值,數(shù)值計算了四種尺寸系數(shù)下的π形斷面,研究尺寸系數(shù)φ對顫振導數(shù)的影響,結(jié)果表明不同風攻角、不同風速下,φ對各個顫振導數(shù)影響有差異,要結(jié)合風攻角與來流風速考察各個顫振導數(shù)隨φ的變化情況;同一風速下,φ對A1、A2、A4三個顫振導數(shù)幾乎沒有影響;當風攻角為0°、+3°、+5°時,φ對H4也沒有影響;其他工況時,尺寸系數(shù)φ對π形斷面的五個顫振導數(shù)影響程度各不相同。
[Abstract]:In the study of wind-induced vibration of bridges, flutter stability analysis is essential. Bridge flutter is self-excited vibration with divergence, once it occurs, it will cause devastating disaster. Flutter derivative is the core of most existing flutter analysis methods. This paper focuses on the flutter derivatives of 蟺 shaped section. Firstly, the wind-induced effects of bridges are briefly introduced, and the development and recent development of flutter stability of bridges are reviewed. The identification theory and method of flutter derivative of bridge section are summarized and analyzed, which provides a theoretical basis for wind tunnel test and numerical simulation in this paper, and introduces the basic theory of computer fluid dynamics. This paper analyzes and determines the algorithm and numerical model of forced vibration in separate states for this paper. Then wind tunnel test and numerical simulation are carried out to identify the flutter derivatives of 蟺 shape main beam section with wind nozzles, and the two results are compared. The numerical results of the four main flutter conductors agree well, and the four auxiliary flutter derivatives vary slightly under individual working conditions. In general, the numerical algorithm in this paper can be used to identify the flutter derivatives of 蟺 shaped sections. The influence of wind attack angle on the eight flutter derivatives of 蟺 shaped section is analyzed. Finally, the dimension coefficient 蠁 of 蟺 shaped section is proposed, which is defined as the ratio of the width of 蟺 shaped section B to the distance between two legs, and the 蟺 shaped section with four dimension coefficients is numerically calculated. The effect of dimension coefficient 蠁 on flutter derivative is studied. The results show that the influence of 蠁 on flutter derivative is different under different wind attack angle and different wind speed. Under the same wind speed, 蠁 has almost no effect on the three flutter derivatives of A _ (1) A _ (2) A _ (2) A _ (4), 蠁 has no effect on H _ 4 when the attack angle is 0 擄, 3 擄and 5 擄, and the influence degree of dimension coefficient 蠁 on the five flutter derivatives of 蟺 section is different under other conditions.
【學位授予單位】：長安大學
【學位級別】：碩士
【學位授予年份】：2015
【分類號】：U441.3

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相關(guān)期刊論文 前1條

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本文編號：1649015