本文選題：環(huán)境激勵(lì) + 動(dòng)力特性參數(shù)　； 參考：《大連海事大學(xué)》2014年碩士論文

【摘要】：橋梁動(dòng)力特性參數(shù)的獲取,對(duì)于分析橋梁結(jié)構(gòu)的抗風(fēng)抗震性能、校核橋梁結(jié)構(gòu)的固有頻率和振型、快速準(zhǔn)確評(píng)價(jià)橋梁健康狀況起到數(shù)據(jù)支持作用,同時(shí)有助于早期發(fā)現(xiàn)橋梁動(dòng)態(tài)病害、降低維修養(yǎng)護(hù)費(fèi)用、加強(qiáng)橋梁的管理,對(duì)于確保橋梁結(jié)構(gòu)使用性能、保證人民生命財(cái)產(chǎn)安全等方面具有重要現(xiàn)實(shí)意義。傳統(tǒng)結(jié)構(gòu)動(dòng)力特性參數(shù)的識(shí)別方法,在識(shí)別過(guò)程中需要同時(shí)得到動(dòng)力測(cè)試響應(yīng)的時(shí)程曲線和激振力數(shù)據(jù),從而利用模態(tài)分析辦法,計(jì)算獲得各個(gè)測(cè)試點(diǎn)處激振力之間的頻率響應(yīng)函數(shù),從而根據(jù)頻域數(shù)據(jù)計(jì)算得到橋梁結(jié)構(gòu)的動(dòng)力特性參數(shù),或者根據(jù)各個(gè)激振力之間的脈沖響應(yīng)函數(shù),根據(jù)數(shù)域數(shù)據(jù)計(jì)算得到結(jié)構(gòu)的動(dòng)力特性參數(shù)。在實(shí)際工程中,大跨度橋梁結(jié)構(gòu)往往采用環(huán)境激勵(lì)法,在動(dòng)力特性測(cè)試中無(wú)法采集到激振力的信號(hào),因此采用傳統(tǒng)動(dòng)力特性參數(shù)識(shí)別辦法無(wú)法直接在環(huán)境激勵(lì)條件下的動(dòng)力響應(yīng)里獲得橋梁結(jié)構(gòu)的動(dòng)力特性參數(shù),需要對(duì)橋梁結(jié)構(gòu)動(dòng)力特性參數(shù)的選取辦法進(jìn)行優(yōu)化。本文根據(jù)隨機(jī)減量技術(shù),在環(huán)境激勵(lì)條件下的隨機(jī)響應(yīng)中獲得結(jié)構(gòu)的自由衰減響應(yīng),在此基礎(chǔ)上,利用小波變換理論形成在自由衰減響應(yīng)條件下,計(jì)算橋梁結(jié)構(gòu)振型和頻率的理論方案。在頻率識(shí)別結(jié)果的基礎(chǔ)上,推導(dǎo)得到了基于自由衰減信號(hào)的橋梁結(jié)構(gòu)各級(jí)阻尼比的理論計(jì)算方法。建立有限元分析模型,結(jié)合工程實(shí)際優(yōu)化設(shè)計(jì)動(dòng)力測(cè)點(diǎn),并對(duì)該橋進(jìn)行環(huán)境激勵(lì),得到該橋梁結(jié)構(gòu)各測(cè)點(diǎn)的動(dòng)力響應(yīng)數(shù)據(jù),基于隨機(jī)減量法獲得動(dòng)力測(cè)點(diǎn)的自由衰減響應(yīng)數(shù)據(jù),進(jìn)而計(jì)算出該橋梁結(jié)構(gòu)的振型、頻率以及阻尼比。最后,本文研究了工程中采用的跑車(chē)試驗(yàn)激勵(lì)條件下橋梁結(jié)構(gòu)沖擊系數(shù)理論計(jì)算,并以某連續(xù)箱梁橋?yàn)槔?進(jìn)行了跑車(chē)試驗(yàn),通過(guò)計(jì)算得出該橋的沖擊系數(shù)。
[Abstract]:The acquisition of bridge dynamic characteristic parameters plays a data support role in analyzing the wind-resistant seismic performance of bridge structure, checking the natural frequency and vibration pattern of bridge structure, and evaluating the bridge health status quickly and accurately. At the same time, it can help to find the bridge dynamic diseases early, reduce the maintenance cost, strengthen the bridge management, ensure the bridge structure performance, ensure the safety of people's life and property and so on. The traditional identification method of structural dynamic characteristic parameters needs to obtain the time history curve and excitation force data of dynamic test response at the same time in the process of identification, so that the modal analysis method is used. The frequency response function of the exciting force at each test point is obtained, and the dynamic characteristic parameters of the bridge structure are calculated according to the frequency domain data, or the impulse response function between the various exciting forces is obtained. The dynamic characteristic parameters of the structure are calculated according to the numerical data. In the actual engineering, the environmental excitation method is often used in the long-span bridge structure, and the signal of the exciting force can not be collected in the dynamic characteristic test. Therefore, the traditional dynamic characteristic parameter identification method can not obtain the dynamic characteristic parameters of the bridge structure directly in the dynamic response under the environmental excitation condition, so it is necessary to optimize the method of selecting the dynamic characteristic parameters of the bridge structure. In this paper, according to the random decrement technique, the free decay response of the structure is obtained in the random response under the environment excitation condition. On this basis, the wavelet transform theory is used to form the free attenuation response condition. A theoretical scheme for calculating the modes and frequencies of bridge structures. Based on the results of frequency identification, the theoretical calculation method of damping ratio of bridge structure based on free attenuation signal is derived. The finite element analysis model is established, the dynamic measuring point is optimized and the dynamic response data of each measuring point of the bridge structure are obtained by the environmental excitation of the bridge, and the free attenuation response data of the dynamic measuring point are obtained based on the random decrement method. Then the vibration mode, frequency and damping ratio of the bridge are calculated. Finally, this paper studies the theoretical calculation of the impact coefficient of bridge structure under the exciting condition of sports car test, and takes a continuous box girder bridge as an example, carries out the sports car test, and obtains the impact coefficient of the bridge by calculation.
【學(xué)位授予單位】：大連海事大學(xué)
【學(xué)位級(jí)別】：碩士
【學(xué)位授予年份】：2014
【分類(lèi)號(hào)】：U441

【參考文獻(xiàn)】

相關(guān)期刊論文 前1條

1 李蕾紅,陸秋海,任革學(xué);特征系統(tǒng)實(shí)現(xiàn)算法的識(shí)別特性研究及算法的推廣[J];工程力學(xué);2002年01期

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本文編號(hào)：1775251