斜拉索風(fēng)雨激振的數(shù)值模擬及基于滑移理論的機(jī)理研究
發(fā)布時(shí)間：2018-07-30 07:17
【摘要】：風(fēng)雨激振是指在風(fēng)雨條件下,斜拉索發(fā)生的低頻率、大振幅的振動(dòng)現(xiàn)象。該現(xiàn)象會(huì)直接破壞斜拉索防腐系統(tǒng),導(dǎo)致斜拉索失效,嚴(yán)重威脅行人及車(chē)輛的安全。根據(jù)近三十年來(lái)諸多學(xué)者的研究表明,斜拉索表面水線形成和振蕩與風(fēng)雨激振現(xiàn)象有重要的關(guān)系。本文首先基于氣液兩相流理論及體積分?jǐn)?shù)法VOF法,研究了不同風(fēng)速對(duì)斜拉索表面水膜的影響,并將不同風(fēng)速時(shí)的水膜運(yùn)動(dòng)與拉索振動(dòng)進(jìn)行單向耦合;然后基于滑移理論推導(dǎo)了二維兩自由度斜拉索風(fēng)雨激振理論模型,實(shí)現(xiàn)了水膜運(yùn)動(dòng)與兩自由度斜拉索振動(dòng)間的雙向耦合;最后基于滑移理論與計(jì)算流體動(dòng)力學(xué)CFD數(shù)值模擬技術(shù),建立了三維斜拉索剛性節(jié)段水膜運(yùn)動(dòng)模型,并通過(guò)正則攝動(dòng)法對(duì)方程進(jìn)行化簡(jiǎn),利用有限差分法求解,得到了不同工況下的水膜運(yùn)動(dòng)情況,從以上三個(gè)角度深入研究了風(fēng)雨激振現(xiàn)象,主要研究?jī)?nèi)容如下:基于氣液兩相流理論及VOF法,計(jì)算了不同風(fēng)速時(shí)二維斜拉索表面的水膜運(yùn)動(dòng)變化情況,得到不同時(shí)刻的上水線及下水線的形成與變化規(guī)律,并通過(guò)后處理得到各時(shí)刻的氣動(dòng)力時(shí)程及頻譜分析,最后將得到氣動(dòng)力升力值施加到斜拉索單質(zhì)點(diǎn)振動(dòng)方程中,得到了不同風(fēng)速時(shí)的斜拉索的振動(dòng)規(guī)律,通過(guò)分析表明,上水線的周期性振蕩是引起風(fēng)雨激振的主要原因;基于滑移理論,建立了兩自由度斜拉索風(fēng)雨激振理論模型,首先考慮斜拉索振動(dòng)在橫風(fēng)向及順風(fēng)向產(chǎn)生的加速度對(duì)水膜形態(tài)變化的影響建立了水膜運(yùn)動(dòng)方程,并利用CFD確定不同時(shí)刻的風(fēng)壓力系數(shù)pC和風(fēng)摩擦力系數(shù)fC?和fzC,考慮了水膜形態(tài)變化導(dǎo)致斜拉索邊界的變化及拉索振動(dòng)引起的氣流場(chǎng)變化,通過(guò)擬譜法求解,實(shí)現(xiàn)了水膜運(yùn)動(dòng)與兩自由度斜拉索振動(dòng)間的雙向耦合,得到了不同時(shí)刻斜拉索順風(fēng)向及橫風(fēng)向的振動(dòng)規(guī)律及上、下水線變化規(guī)律,通過(guò)與單自由度斜拉索風(fēng)雨激振結(jié)果進(jìn)行比較,發(fā)現(xiàn)兩自由度斜拉索在橫風(fēng)向及順風(fēng)向均發(fā)生了大幅度的振動(dòng)現(xiàn)象,其周?chē)臍鈩?dòng)力也發(fā)生了周期性的變化,而拉索表面上、下水線也出現(xiàn)了明顯的周期性振蕩,通過(guò)頻譜分析發(fā)現(xiàn)拉索的振動(dòng)頻率與拉索周?chē)臍鈩?dòng)力變化頻率、水線的振蕩頻率非常接近,且均接近于拉索的自振頻率;考慮斜拉索氣流及水流沿軸向的影響,基于滑移理論建立了三維斜拉索剛性節(jié)段水膜運(yùn)動(dòng)方程,利用正則攝動(dòng)法對(duì)方程進(jìn)行化簡(jiǎn),忽略高階項(xiàng),并采用有限差分法中的交替方向隱式差分格式(ADI格式)進(jìn)行數(shù)值求解;通過(guò)計(jì)算水平及豎直放置的斜拉索在僅受重力作用下斜拉索表面水膜的運(yùn)動(dòng)變化情況證明了該方法的準(zhǔn)確性,然后計(jì)算了不同風(fēng)速時(shí),斜拉索表面水膜的分布及形態(tài)變化,通過(guò)研究發(fā)現(xiàn)該方法能很好的模擬水膜在三維斜拉索表面的運(yùn)動(dòng)變化規(guī)律,只有當(dāng)風(fēng)速增大到一定程度時(shí),才會(huì)出現(xiàn)上水線,且上水線的位置變化受風(fēng)速和重力的影響明顯大于下水線。
[Abstract]:Wind and rain excitation is the phenomenon of low frequency and large amplitude vibration caused by cable in wind and rain conditions. This phenomenon will directly destroy the anticorrosion system of inclined cable, cause the failure of the cable cable and seriously threaten the safety of pedestrians and vehicles. According to the research of many scholars in recent thirty years, the formation and oscillation of the surface of the cable surface and the wind and rain induced vibration are shown. In this paper, based on the gas-liquid two-phase flow theory and the volume fraction VOF method, the influence of different wind speeds on the water film on the cable surface is studied, and the unidirectional coupling of the water film motion and the cable vibration at different wind speeds is carried out, and the theoretical model of the two dimension two degree of freedom cable wind and rain induced vibration is derived based on the slip theory. The bi-directional coupling between the motion of water film and the vibration of two degree of freedom cable-stayed cable is presented. Finally, based on the sliding theory and the computational fluid dynamics CFD numerical simulation technology, a three-dimensional water film motion model of the rigid segment of the cable is established, and the equation is simplified by the regular perturbation method, and the water film under different conditions is obtained by the finite difference method. The main research contents are as follows: Based on the theory of gas-liquid two phase flow and VOF method, the change of water film movement on the surface of two dimensional cable-stayed cable is calculated based on the gas liquid two-phase flow theory and VOF method, and the formation and change rules of the water line and the lower water line at different times are obtained. At the moment, the aerodynamic time history and spectrum analysis, the aerodynamic lift value is applied to the single point vibration equation of the cable-stayed cable, and the vibration law of the cable-stayed cable with different wind speeds is obtained. Through the analysis, the periodic oscillation of the water line is the main cause of the wind and rain excitation. Based on the slip theory, a two degree of freedom cable-stayed cable is established. In the theoretical model of wind and rain excitation, the equation of water film motion is established by considering the effect of the acceleration of the cable in the wind direction and the wind direction on the change of the shape of the water film. The wind pressure coefficient pC and the wind friction coefficient fC? And fzC are determined by CFD. The change of the flow field caused by the cable vibration is solved by the pseudospectral method. The two-way coupling between the water film movement and the two degree of freedom cable-stayed cable vibration is realized, and the vibration laws of the wind direction and the cross wind direction of the cable are obtained at different time, and the law of the change of the lower water line is obtained. By comparing the results of the wind and rain induced vibration with the single degree of freedom cable, it is found that two freedom is found. There is a large amplitude vibration phenomenon in the cross wind direction and the wind direction, and the aerodynamic force also changes periodically. On the surface of the cable, the lower water line also has obvious periodic oscillation. The frequency of the vibration of the cable and the frequency of the aerodynamic change of the cable circumference are found through the spectrum analysis. The oscillation frequency of the water line is not. It is close to and close to the vibration frequency of the cable. Considering the influence of the air flow and the flow along the axial direction of the cable, the motion equation of the three dimensional rigid segment of the cable is established based on the slip theory. The regular perturbation method is used to simplify the equation, ignore the high order, and use the alternating direction implicit difference scheme (ADI format) in the finite difference method. Numerical solution is carried out, and the accuracy of the method is proved by calculating the movement of the water film on the surface of the inclined cable surface under the action of gravity only. Then the distribution and morphological changes of the water film on the surface of the cable surface are calculated when different wind speeds have been calculated. It is found that the method can simulate the water film in three dimensions well. The change rule of the motion of the cable surface is only when the wind speed increases to a certain degree, and the change of the position of the water line is greatly influenced by the wind speed and the gravity.
【學(xué)位授予單位】：天津大學(xué)
【學(xué)位級(jí)別】：博士
【學(xué)位授予年份】：2014
【分類(lèi)號(hào)】：U441.3;U448.27
[Abstract]:Wind and rain excitation is the phenomenon of low frequency and large amplitude vibration caused by cable in wind and rain conditions. This phenomenon will directly destroy the anticorrosion system of inclined cable, cause the failure of the cable cable and seriously threaten the safety of pedestrians and vehicles. According to the research of many scholars in recent thirty years, the formation and oscillation of the surface of the cable surface and the wind and rain induced vibration are shown. In this paper, based on the gas-liquid two-phase flow theory and the volume fraction VOF method, the influence of different wind speeds on the water film on the cable surface is studied, and the unidirectional coupling of the water film motion and the cable vibration at different wind speeds is carried out, and the theoretical model of the two dimension two degree of freedom cable wind and rain induced vibration is derived based on the slip theory. The bi-directional coupling between the motion of water film and the vibration of two degree of freedom cable-stayed cable is presented. Finally, based on the sliding theory and the computational fluid dynamics CFD numerical simulation technology, a three-dimensional water film motion model of the rigid segment of the cable is established, and the equation is simplified by the regular perturbation method, and the water film under different conditions is obtained by the finite difference method. The main research contents are as follows: Based on the theory of gas-liquid two phase flow and VOF method, the change of water film movement on the surface of two dimensional cable-stayed cable is calculated based on the gas liquid two-phase flow theory and VOF method, and the formation and change rules of the water line and the lower water line at different times are obtained. At the moment, the aerodynamic time history and spectrum analysis, the aerodynamic lift value is applied to the single point vibration equation of the cable-stayed cable, and the vibration law of the cable-stayed cable with different wind speeds is obtained. Through the analysis, the periodic oscillation of the water line is the main cause of the wind and rain excitation. Based on the slip theory, a two degree of freedom cable-stayed cable is established. In the theoretical model of wind and rain excitation, the equation of water film motion is established by considering the effect of the acceleration of the cable in the wind direction and the wind direction on the change of the shape of the water film. The wind pressure coefficient pC and the wind friction coefficient fC? And fzC are determined by CFD. The change of the flow field caused by the cable vibration is solved by the pseudospectral method. The two-way coupling between the water film movement and the two degree of freedom cable-stayed cable vibration is realized, and the vibration laws of the wind direction and the cross wind direction of the cable are obtained at different time, and the law of the change of the lower water line is obtained. By comparing the results of the wind and rain induced vibration with the single degree of freedom cable, it is found that two freedom is found. There is a large amplitude vibration phenomenon in the cross wind direction and the wind direction, and the aerodynamic force also changes periodically. On the surface of the cable, the lower water line also has obvious periodic oscillation. The frequency of the vibration of the cable and the frequency of the aerodynamic change of the cable circumference are found through the spectrum analysis. The oscillation frequency of the water line is not. It is close to and close to the vibration frequency of the cable. Considering the influence of the air flow and the flow along the axial direction of the cable, the motion equation of the three dimensional rigid segment of the cable is established based on the slip theory. The regular perturbation method is used to simplify the equation, ignore the high order, and use the alternating direction implicit difference scheme (ADI format) in the finite difference method. Numerical solution is carried out, and the accuracy of the method is proved by calculating the movement of the water film on the surface of the inclined cable surface under the action of gravity only. Then the distribution and morphological changes of the water film on the surface of the cable surface are calculated when different wind speeds have been calculated. It is found that the method can simulate the water film in three dimensions well. The change rule of the motion of the cable surface is only when the wind speed increases to a certain degree, and the change of the position of the water line is greatly influenced by the wind speed and the gravity.
【學(xué)位授予單位】：天津大學(xué)
【學(xué)位級(jí)別】：博士
【學(xué)位授予年份】：2014
【分類(lèi)號(hào)】：U441.3;U448.27
【相似文獻(xiàn)】
相關(guān)期刊論文 前10條
1 蘇達(dá)根,高德虎,張志杰;斜拉索失效原因分析[J];工業(yè)建筑;1999年09期
2 李國(guó)平;斜拉索非線性分析的狀態(tài)修正法[J];同濟(jì)大學(xué)學(xué)報(bào)(自然科學(xué)版);2000年01期
3 劉萬(wàn)鋒,劉健新;斜拉索粘性剪切型阻尼器的簡(jiǎn)化設(shè)計(jì)方法[J];西安公路交通大學(xué)學(xué)報(bào);2000年04期
4 潘鈞俊,林雪綱,莊表中,孫f，
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