分離式雙箱梁風(fēng)致振動全過程流場研究
發(fā)布時間：2018-08-26 13:36
【摘要】：分離式雙箱梁是一種較為新型的大跨度懸索橋主梁斷面形式,具有良好的氣動穩(wěn)定性,與傳統(tǒng)的整體式箱梁相比,其顫振臨界風(fēng)速較高,但對于渦激振動更為敏感。從現(xiàn)場監(jiān)測資料可以看出,采用分離式雙箱梁斷面的某大跨度懸索橋在5m/s至10m/s的風(fēng)速范圍內(nèi)渦激振動現(xiàn)象較為明顯。目前對于誘導(dǎo)分離式雙箱梁橋發(fā)生風(fēng)致振動的原因仍沒有清晰的解釋,尤其是從流場的角度,目前仍缺乏全面、深入的分析。本文對分離式雙箱梁懸索橋風(fēng)致振動全過程進(jìn)行研究,以某大跨度懸索橋為對象,進(jìn)行彈性節(jié)段模型風(fēng)洞試驗研究。試驗采用1:200的幾何縮尺比模型,測量了模型在0°風(fēng)攻角層流風(fēng)下的風(fēng)致振動響應(yīng)特性,并采用粒子圖像測速(Particle Image Velocimetry,PIV)系統(tǒng)觀測了結(jié)構(gòu)發(fā)生渦激共振及顫振時的繞流流場,以研究渦振及顫振過程的繞流場特征。具體研究內(nèi)容所如下:1.測量結(jié)構(gòu)的靜態(tài)流場特征,研究不同風(fēng)攻角下的分離式雙箱梁繞流場形態(tài)。2.測量結(jié)構(gòu)發(fā)生渦激共振時的振動響應(yīng)特征及繞流場特性,對比不同風(fēng)速下的振動響應(yīng)及流場特征,研究流場形態(tài)與結(jié)構(gòu)振動的相互作用。3.測量結(jié)構(gòu)發(fā)生顫振時的振動響應(yīng)特征及繞流場特性,對比不同風(fēng)速下的振動響應(yīng)及流場特征,研究流場形態(tài)與結(jié)構(gòu)振動的相互作用。試驗結(jié)果顯示,分離式雙箱梁懸索橋在較低風(fēng)速下會發(fā)生豎向及扭轉(zhuǎn)兩個方向的單自由度渦激共振,而豎向和扭轉(zhuǎn)各自存在兩個不同的鎖定風(fēng)速范圍,結(jié)構(gòu)振動頻率均與結(jié)構(gòu)固有的豎向、扭轉(zhuǎn)頻率相同;結(jié)構(gòu)在較高風(fēng)速下會發(fā)生豎向、扭轉(zhuǎn)兩個自由度的耦合顫振,此時豎向和扭轉(zhuǎn)頻率彼此相同,在氣動阻尼的影響下又異于結(jié)構(gòu)自身固有頻率。通過對結(jié)構(gòu)繞流氣流速度場的識別得到了結(jié)構(gòu)風(fēng)致振動全過程的流場變化,包括旋渦的生成、傳遞和脫落過程,進(jìn)而對旋渦特征進(jìn)行量化計算以分析結(jié)構(gòu)振動和流場之間的相互作用。
[Abstract]:Split double box girder is a new type of long span suspension bridge main girder section form, with good aerodynamic stability, compared with the traditional integral box girder, its flutter critical wind speed is higher, but more sensitive to vortex-induced vibration. From the field monitoring data, it can be seen that the vortex-induced vibration of a long-span suspension bridge with split double box girder section is obvious in the range of wind speed from 5m/s to 10m/s. At present, there is still no clear explanation for the wind-induced vibration of the separated double-box-girder bridge, especially from the point of view of the flow field, there is still a lack of comprehensive and in-depth analysis. In this paper, the wind-induced vibration of a separated double-box-girder suspension bridge is studied. The wind tunnel test of a long-span suspension bridge is carried out with an elastic segmental model. The wind induced vibration response of the model under the wind of 0 擄wind angle of attack is measured by using the geometric scale ratio model of 1: 200, and the flow field around the structure with vortex-induced resonance and flutter is observed by particle image velocimetry (Particle Image Velocimetry,PIV) system. In order to study the characteristics of vortex vibration and flutter around the flow field. The specific contents of the study are as follows: 1. The static flow field characteristics of the structure are measured, and the flow field around the separated double box girder with different wind attack angles is studied. The characteristics of vibration response and flow field around a structure with vortex-induced resonance are measured. The interaction between flow field shape and structure vibration is studied by comparing the vibration response and flow field characteristics under different wind speeds. The characteristics of vibration response and flow field around the structure were measured, and the interaction between the flow field and the structure vibration was studied by comparing the vibration response and the flow field characteristics under different wind speeds. The experimental results show that single degree of freedom vortex-induced resonance occurs in the vertical and torsional directions of the separated double-box-girder suspension bridge under lower wind speed, while the vertical and torsional wind have two different locked wind speed ranges. The vibration frequency of the structure is the same as that of the vertical direction of the structure and the torsional frequency of the structure is the same as that of the structure, and the vertical vibration frequency of the structure is the same as that of the torsional frequency at the higher wind speed, and the coupled flutter of two degrees of freedom is torsional. Under the influence of aerodynamic damping, it is different from the natural frequency of the structure itself. Through the identification of the velocity field of the flow around the structure, the variation of the flow field in the whole process of the wind-induced vibration of the structure is obtained, including the generation, transfer and shedding of vortex. Then the vortex characteristics are quantitatively calculated to analyze the interaction between the structure vibration and the flow field.
【學(xué)位授予單位】：哈爾濱工業(yè)大學(xué)
【學(xué)位級別】：碩士
【學(xué)位授予年份】：2015
【分類號】：U441.3;U448.213
本文編號：2205021
[Abstract]:Split double box girder is a new type of long span suspension bridge main girder section form, with good aerodynamic stability, compared with the traditional integral box girder, its flutter critical wind speed is higher, but more sensitive to vortex-induced vibration. From the field monitoring data, it can be seen that the vortex-induced vibration of a long-span suspension bridge with split double box girder section is obvious in the range of wind speed from 5m/s to 10m/s. At present, there is still no clear explanation for the wind-induced vibration of the separated double-box-girder bridge, especially from the point of view of the flow field, there is still a lack of comprehensive and in-depth analysis. In this paper, the wind-induced vibration of a separated double-box-girder suspension bridge is studied. The wind tunnel test of a long-span suspension bridge is carried out with an elastic segmental model. The wind induced vibration response of the model under the wind of 0 擄wind angle of attack is measured by using the geometric scale ratio model of 1: 200, and the flow field around the structure with vortex-induced resonance and flutter is observed by particle image velocimetry (Particle Image Velocimetry,PIV) system. In order to study the characteristics of vortex vibration and flutter around the flow field. The specific contents of the study are as follows: 1. The static flow field characteristics of the structure are measured, and the flow field around the separated double box girder with different wind attack angles is studied. The characteristics of vibration response and flow field around a structure with vortex-induced resonance are measured. The interaction between flow field shape and structure vibration is studied by comparing the vibration response and flow field characteristics under different wind speeds. The characteristics of vibration response and flow field around the structure were measured, and the interaction between the flow field and the structure vibration was studied by comparing the vibration response and the flow field characteristics under different wind speeds. The experimental results show that single degree of freedom vortex-induced resonance occurs in the vertical and torsional directions of the separated double-box-girder suspension bridge under lower wind speed, while the vertical and torsional wind have two different locked wind speed ranges. The vibration frequency of the structure is the same as that of the vertical direction of the structure and the torsional frequency of the structure is the same as that of the structure, and the vertical vibration frequency of the structure is the same as that of the torsional frequency at the higher wind speed, and the coupled flutter of two degrees of freedom is torsional. Under the influence of aerodynamic damping, it is different from the natural frequency of the structure itself. Through the identification of the velocity field of the flow around the structure, the variation of the flow field in the whole process of the wind-induced vibration of the structure is obtained, including the generation, transfer and shedding of vortex. Then the vortex characteristics are quantitatively calculated to analyze the interaction between the structure vibration and the flow field.
【學(xué)位授予單位】：哈爾濱工業(yè)大學(xué)
【學(xué)位級別】：碩士
【學(xué)位授予年份】：2015
【分類號】：U441.3;U448.213
【參考文獻(xiàn)】
相關(guān)期刊論文 前1條
1 楊奰昕;葛耀君;項海帆;;平板斷面扭彎耦合顫振機(jī)理研究[J];工程力學(xué);2006年12期
，本文編號：2205021
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