【摘要】：大跨度懸索橋由于其剛度較小，在風(fēng)、車輛等外荷載作用下會(huì)產(chǎn)生較大的內(nèi)力和變形。因此，對(duì)大跨度懸索橋進(jìn)行動(dòng)力分析，無(wú)論是對(duì)橋梁的設(shè)計(jì)還是維護(hù)，都有重要的意義。 本文以矮寨大橋?yàn)橐劳�，建立了三維橋梁有限元模型，綜合考慮車輛與風(fēng)荷載的作用，對(duì)大跨度橋梁的動(dòng)力響應(yīng)進(jìn)行了分析。全文主要包括以下幾方面內(nèi)容： 1.在時(shí)域內(nèi)模擬了我國(guó)常見(jiàn)的4種路面不平順；采用諧波疊加法模擬了橋址處的風(fēng)速場(chǎng)。 2.分析了車輛荷載單獨(dú)作用下橋梁的動(dòng)力響應(yīng)，得到以下結(jié)論： 1）隨著路面不平順等級(jí)的增大，橋梁跨中豎向位移、加速度時(shí)程曲線振動(dòng)趨勢(shì)隨之變化，同時(shí)動(dòng)力響應(yīng)峰值會(huì)隨之增大，且位移、加速度增長(zhǎng)倍數(shù)相近。 2）隨著車速的提高，橋梁跨中豎向位移、加速度時(shí)程曲線振動(dòng)趨勢(shì)也隨之變化，同時(shí)動(dòng)力響應(yīng)峰值也呈增長(zhǎng)趨勢(shì)，其中加速度的增長(zhǎng)速度要大于位移的。 3）隨著車重的增加，，橋梁跨中豎向位移、加速度時(shí)程曲線振動(dòng)趨勢(shì)幾乎沒(méi)變化，且動(dòng)力響應(yīng)呈線性增長(zhǎng)。 4）橋梁跨中橫向動(dòng)力響應(yīng)的產(chǎn)生主要來(lái)自橋梁兩側(cè)的不平衡力，不平衡性越大，動(dòng)力響應(yīng)越大。 3.通過(guò)一簡(jiǎn)支梁、半車模型，分析了車輛上橋前的初始振動(dòng)對(duì)橋梁動(dòng)力響應(yīng)的影響，同時(shí)對(duì)車輛變速行駛的問(wèn)題進(jìn)行了研究。得到以下結(jié)論： 1）與無(wú)初始振動(dòng)的情況相比，車輛帶著一定的初始振動(dòng)上橋，剛?cè)霕虻囊欢螘r(shí)間內(nèi)，橋梁的動(dòng)力響應(yīng)會(huì)明顯增大，隨著車輛繼續(xù)行駛，這種影響會(huì)慢慢減弱。 2）車輛變速行駛對(duì)橋梁動(dòng)力響應(yīng)的影響不大，在實(shí)際計(jì)算中，我們可以不考慮車輛變速行駛的影響。 4.分析了風(fēng)荷載單獨(dú)作用及風(fēng)和車輛荷載同時(shí)作用下橋梁的動(dòng)力響應(yīng)。得到如下結(jié)論： 1）隨著風(fēng)速的增大，橋梁跨中節(jié)點(diǎn)各項(xiàng)動(dòng)力響應(yīng)均呈增長(zhǎng)趨勢(shì)。 2）在風(fēng)荷載作用下，迎風(fēng)面腹桿和背風(fēng)面腹桿應(yīng)力時(shí)程曲線呈現(xiàn)相反的變化趨勢(shì)，且在同種風(fēng)速下，背風(fēng)面腹桿應(yīng)力峰值大于迎風(fēng)面的情況。 3）風(fēng)荷載主要引起橋梁的橫向振動(dòng)，車輛荷載主要引起橋梁的豎向振動(dòng)。 4）靜風(fēng)荷載使橋梁向一側(cè)偏移，脈動(dòng)風(fēng)在此基礎(chǔ)上使橋梁發(fā)生振動(dòng)，隨著風(fēng)速的增大，偏移量和振動(dòng)都呈增大趨勢(shì)。
[Abstract]:Due to the small stiffness of long-span suspension bridge, large internal force and deformation will occur under external loads such as wind and vehicle. Therefore, the dynamic analysis of long-span suspension bridge is of great significance to the design and maintenance of the bridge. In this paper, based on the Aizhai Bridge, a three-dimensional finite element model of the bridge is established, and the dynamic response of the long-span bridge is analyzed synthetically considering the action of vehicle and wind load. The full text mainly includes the following aspects: 1. In this paper, four kinds of road surface irregularity are simulated in time domain, and the wind velocity field at bridge site is simulated by harmonic superposition method. 2. 2. The dynamic response of the bridge under vehicle load alone is analyzed. The following conclusions are obtained: 1) with the increase of the road surface irregularity grade, the vertical displacement and acceleration time history curve vibration trend of the bridge span changes with the increase of the road surface irregularity grade. At the same time, the peak value of dynamic response will increase, and the displacement and acceleration increase times will be similar. 2) with the increase of speed, the vertical displacement of bridge span and the vibration trend of acceleration time history curve will also change. At the same time, the peak value of dynamic response also shows an increasing trend, in which the acceleration increases faster than the displacement. 3) with the increase of the vehicle weight, the vertical displacement of the bridge span and the vibration trend of the acceleration time-history curve are almost unchanged. And the dynamic response increases linearly. 4) the transverse dynamic response of the bridge is generated mainly from the unbalanced force on both sides of the bridge. The greater the unbalance, the greater the dynamic response. Based on a simply supported beam and half-car model, the influence of the initial vibration on the dynamic response of the bridge is analyzed. At the same time, the problem of vehicle driving with variable speed is studied. The following conclusions are obtained: 1) compared with the case of no initial vibration, the dynamic response of the bridge will increase obviously when the vehicle is on the bridge with a certain initial vibration, and the dynamic response of the bridge will increase obviously as the vehicle continues to drive. This effect will weaken slowly. 2) the effect of vehicle speed change on bridge dynamic response is not significant. In actual calculation, we can not consider the effect of vehicle speed change. 4. The dynamic response of the bridge under the action of wind load alone and the simultaneous action of wind and vehicle loads is analyzed. The main conclusions are as follows: 1) with the increase of wind speed, the dynamic responses of the mid-span joints of the bridge show an increasing trend. 2) under the action of wind load, The stress time history curves of upwind and leeward webs show a reverse trend, and the peak stress of leeward web is larger than that of upwind under the same wind speed. 3) the transverse vibration of bridges is mainly caused by wind load. The vehicle load mainly causes the vertical vibration of the bridge. 4) the static wind load causes the bridge to deviate to one side, and the pulsating wind makes the bridge vibrate on this basis. With the increase of the wind speed, the deviation and vibration tend to increase.
【學(xué)位授予單位】：鄭州大學(xué)
【學(xué)位級(jí)別】：碩士
【學(xué)位授予年份】：2014
【分類號(hào)】：U448.25;U441.3

【參考文獻(xiàn)】

相關(guān)期刊論文 前10條

1 劉云;錢振東;;路面平整度及車輛振動(dòng)模型的研究綜述[J];公路交通科技;2008年01期

2 王運(yùn)金;桂水榮;陳水生;;連續(xù)梁橋車橋耦合振動(dòng)分析的數(shù)值解法[J];華東交通大學(xué)學(xué)報(bào);2007年04期

3 張軍,江克斌,胡業(yè)平;車橋耦合動(dòng)力學(xué)系統(tǒng)模態(tài)綜合分析[J];解放軍理工大學(xué)學(xué)報(bào)(自然科學(xué)版);2003年01期

4 程保榮,周玉勛;車橋耦合系統(tǒng)動(dòng)力分析的模態(tài)綜合技術(shù)[J];清華大學(xué)學(xué)報(bào)(自然科學(xué)版);2002年08期

5 金睿臣，宋健;路面不平度的模擬與汽車非線性隨機(jī)振動(dòng)的研究[J];清華大學(xué)學(xué)報(bào)(自然科學(xué)版);1999年08期

6 李永樂(lè),強(qiáng)士中,廖海黎;考慮車輛位置影響的風(fēng)-車-橋系統(tǒng)耦合振動(dòng)研究[J];橋梁建設(shè);2004年03期

7 楊建榮;李建中;范立礎(chǔ);;車橋耦合振動(dòng)分析的兩種常用插值方法比較[J];力學(xué)季刊;2007年04期

8 譚國(guó)輝;橋梁與車輛相互作用的系統(tǒng)模擬[J];土木工程學(xué)報(bào);1996年03期

9 曹映泓,項(xiàng)海帆,周穎;大跨度橋梁隨機(jī)風(fēng)場(chǎng)的模擬[J];土木工程學(xué)報(bào);1998年03期

10 余華;吳定俊;;Hermite插值在車橋耦合振動(dòng)中的應(yīng)用[J];振動(dòng)與沖擊;2006年02期

本文編號(hào)：2225579