【摘要】：提出本研究的意圖是系統(tǒng)的動力性能研究及其應(yīng)用,該研究可以概括為系統(tǒng)仿真和系統(tǒng)動力測試兩部分,前者主要是理論研究,比如系統(tǒng)的動力模型、運(yùn)動方程和解答,后者主要圍繞實(shí)驗(yàn)展開,比如結(jié)構(gòu)動力測試技術(shù),系統(tǒng)參數(shù)識別方法。文章結(jié)合這兩方面的問題展開,并著重在信號處理原理,參數(shù)識別方法上進(jìn)行了深入探討,對鋼筋混凝土受彎構(gòu)件進(jìn)行了動力測試,依據(jù)測試數(shù)據(jù)識別得到結(jié)構(gòu)的動力參數(shù),總結(jié)測試技術(shù)和結(jié)構(gòu)動力性能兩方面的規(guī)律。研究的主要工作簡述如下： 對鋼筋混凝土受彎構(gòu)件的分級靜力加卸載性能進(jìn)行了細(xì)致測試,得到構(gòu)件隨荷載增加剛度下降的真實(shí)變化曲線,結(jié)合相關(guān)研究推測構(gòu)件彎曲剛度函數(shù)的主要特征,為理論研究和實(shí)際應(yīng)用提供基本事實(shí)依據(jù)。首先只要當(dāng)前荷載不大于結(jié)構(gòu)經(jīng)歷過的最大荷載,受彎構(gòu)件的荷載-撓度關(guān)系基本符合線性特征,依據(jù)動力測試數(shù)據(jù)識別結(jié)構(gòu)動力參數(shù),一般構(gòu)件在荷載-撓度曲線上的非線性都比較弱,假設(shè)的結(jié)構(gòu)模型與測試數(shù)據(jù)不符合時,多考慮其以外的其他因素,其次構(gòu)件開裂截面上剛度下降所影響的區(qū)域也往往較小。 從傅立葉級數(shù)推導(dǎo)出離散傅立葉變換(DFT)表達(dá)式,對DFT物理意義進(jìn)行了清晰完整的解釋,采用不同的DFT表達(dá)式計(jì)算信號頻譜時,只需相應(yīng)調(diào)整頻譜系數(shù)和頻域坐標(biāo)。在原理上澄清了頻譜的對稱性質(zhì),盡管有效譜線數(shù)N／2這個籠統(tǒng)的數(shù)字一般不會遺漏關(guān)鍵譜線,但有可能影響到對其他相關(guān)問題的理解,比如在頻域計(jì)算過程中,會混淆數(shù)量關(guān)系；在討論DFT物理意義的基礎(chǔ)上進(jìn)一步討論了定頻的改進(jìn)方法：細(xì)化頻譜分析。同時由理論推導(dǎo)發(fā)現(xiàn)了細(xì)化頻譜與連續(xù)矩形窗頻譜有極大相似之處,以連續(xù)矩形窗頻譜曲線為樣板,提出了一般保守信號細(xì)化頻譜的量化特征,并在解決密集頻率頻譜的判定和分離的問題中得到應(yīng)用。 通過細(xì)化頻譜分析識別信號的頻率和初相位,利用DFT的重要性質(zhì)：離散卷積和反卷積原理。提出一種從自由衰減響應(yīng)(FDR)中提取阻尼特性的新方法,本方法在對阻尼特性進(jìn)行提取之前不需要對阻尼模型進(jìn)行假設(shè),提取FDR中各頻率諧波的振幅隨時間變化的時域序列,能夠更加真實(shí)的揭示系統(tǒng)的阻尼特性,該方法主要對獨(dú)立頻率頻譜比較適用。對于密集頻率頻譜,參考離散反卷積方法得到的識別結(jié)果,設(shè)定諧波參數(shù)范圍和步長,把這些參數(shù)循環(huán)代入指定理論信號表達(dá)式中,尋找能使理論信號與實(shí)驗(yàn)信號的頻域曲線最相近的參數(shù)組合確定為最優(yōu)結(jié)果,實(shí)現(xiàn)了只用結(jié)構(gòu)的響應(yīng)信號識別系統(tǒng)模態(tài)參數(shù)的預(yù)想。 對鋼筋混凝土框架、普通鋼筋混凝土簡支梁和組合梁進(jìn)行了動力實(shí)驗(yàn),依據(jù)對實(shí)驗(yàn)測試數(shù)據(jù)的計(jì)算結(jié)果,討論了不同測試條件對測試結(jié)果的影響,總結(jié)了動力測試技術(shù)和結(jié)構(gòu)的動力性能兩方面的規(guī)律；在用動力方法對結(jié)構(gòu)進(jìn)行損傷診斷時,得到了模態(tài)參數(shù)隨結(jié)構(gòu)損傷的變化規(guī)律：各頻率隨損傷增加不斷下降,其中高頻的下降量較大,阻尼的指數(shù)衰減系數(shù),在正常使用階段也有隨損傷增加而增加的趨勢,高階模態(tài)的趨勢更大。頻率和阻尼對判斷結(jié)構(gòu)的狀態(tài)都有一定指示作用,而模態(tài)振型可以幫助判斷重復(fù)模態(tài)。
[Abstract]:The purpose of this study is to study the dynamic performance of the system and its application. The study can be summarized as two parts: system simulation and system dynamic test. The former is mainly theoretical research, such as dynamic model, motion equation and solution of the system. The latter is mainly carried out around experiments, such as structural dynamic test technology, system parameter identification method. This paper combines these two problems, and focuses on the principle of signal processing and parameter identification method. The dynamic test of reinforced concrete flexural members is carried out. The dynamic parameters of the structure are identified according to the test data. The main work of the research is summarized in the aspects of testing technology and structural dynamic performance. The following are briefly stated:
The static loading and unloading performance of reinforced concrete flexural members is tested in detail, and the real change curve of the stiffness of the members decreases with the increase of load is obtained. The main characteristics of the flexural stiffness function of the members are deduced by combining with relevant research, which provides the basic factual basis for theoretical research and practical application. The load-deflection relationship of the flexural member is basically linear under the maximum load experienced by the structure. The dynamic parameters of the structure are identified according to the dynamic test data. Generally, the nonlinearity of the members on the load-deflection curve is weak. When the assumed structural model does not conform to the test data, the factors other than the load-deflection relationship should be considered, and then the cracking of the members should be considered. The decrease of stiffness on the cross section also tends to be smaller.
The expression of discrete Fourier transform (DFT) is deduced from Fourier series. The physical meaning of DFT is explained clearly and completely. When different DFT expressions are used to calculate the signal spectrum, only the spectrum coefficients and the frequency domain coordinates need to be adjusted accordingly. The symmetry property of spectrum is clarified in principle, although the general figure N/2 is the effective spectral line number. In general, the key spectral lines will not be omitted, but it may affect the understanding of other related problems, such as confusing the quantitative relationship in the frequency domain calculation process; on the basis of discussing the physical meaning of DFT, the paper further discusses the improved method of frequency determination: the refined spectral analysis. The spectrum has great similarity. Taking the spectrum curve of continuous rectangular window as a model, the quantization characteristics of general conservative signal thinning spectrum are proposed and applied to the determination and separation of dense frequency spectrum.
Frequency and initial phase of signals are identified by spectral analysis, and a new method of extracting damping characteristics from free attenuation response (FDR) is proposed based on the discrete convolution and deconvolution principle, which is an important property of DFT. The time-domain sequence of amplitudes varying with time can reveal the damping characteristics of the system more truly. This method is mainly suitable for the independent frequency spectrum. For the dense frequency spectrum, the range and step size of harmonic parameters are set according to the identification results obtained by the discrete deconvolution method, and these parameters are cyclically substituted into the specified theoretical signal expression. In the formula, the optimal result is obtained by finding the parameter combination which can make the frequency domain curve of the theoretical signal and the experimental signal the closest.
The dynamic experiment of reinforced concrete frame, ordinary reinforced concrete simply supported beam and composite beam is carried out. Based on the calculation results of experimental test data, the influence of different test conditions on test results is discussed, and the rules of dynamic test technology and dynamic performance of structure are summarized. At break time, the variation law of modal parameters with structural damage is obtained: the frequency decreases with the increase of damage, and the high frequency decreases more, the exponential damping coefficient of damping increases with the increase of damage, and the trend of high-order modal is larger. Frequency and damping have certain influence on judging the state of structure. The mode of vibration can help to judge repetitive modes.
【學(xué)位授予單位】：湖南大學(xué)
【學(xué)位級別】：博士
【學(xué)位授予年份】：2014
【分類號】：TU375;TU311.3

【參考文獻(xiàn)】

相關(guān)期刊論文 前10條

1 肖詩云,林皋,王哲,逯靜洲;應(yīng)變率對混凝土抗拉特性影響[J];大連理工大學(xué)學(xué)報(bào);2001年06期

2 羅利春;;Zoom-FFT的改進(jìn)、頻譜反演與時-頻局部化特性[J];電子學(xué)報(bào);2006年01期

3 陳東弟;向家偉;;運(yùn)行模態(tài)分析方法綜述[J];桂林電子科技大學(xué)學(xué)報(bào);2010年02期

4 潘芹,袁賢訊;靜、動力剛度關(guān)系在RC簡支梁動力損傷診斷中的應(yīng)用[J];廣西民族學(xué)院學(xué)報(bào)(自然科學(xué)版);2002年04期

5 周奎;王琦;劉衛(wèi)東;張簡;;土木工程結(jié)構(gòu)健康監(jiān)測的研究進(jìn)展綜述[J];工業(yè)建筑;2009年03期

6 王政;倪玉山;曹菊珍;張文;;沖擊載荷下混凝土本構(gòu)模型構(gòu)建研究[J];高壓物理學(xué)報(bào);2006年04期

7 肖詩云,林皋,逯靜洲,王哲;應(yīng)變率對混凝土抗壓特性的影響[J];哈爾濱建筑大學(xué)學(xué)報(bào);2002年05期

8 易偉健;工程結(jié)構(gòu)損傷診斷的動力學(xué)方法研究綜述[J];湖南城建高等專科學(xué)校學(xué)報(bào);1999年03期

9 胡嵐;馬克儉;;U形鋼板-混凝土高強(qiáng)螺栓連接組合空腹夾層板樓蓋結(jié)構(gòu)研究與應(yīng)用[J];建筑結(jié)構(gòu)學(xué)報(bào);2012年07期

10 王時越,張立翔,徐人平,趙造東;混凝土疲勞剛度衰減規(guī)律試驗(yàn)研究[J];力學(xué)與實(shí)踐;2003年05期

相關(guān)博士學(xué)位論文 前2條

1 周云;地基板與混凝土框架結(jié)構(gòu)參數(shù)識別的實(shí)驗(yàn)與研究[D];湖南大學(xué);2008年

2 劉慕廣;兩類大長細(xì)比橋梁構(gòu)件的風(fēng)振特性研究[D];湖南大學(xué);2009年

，

本文編號：2240335