最大熵譜在空間網(wǎng)格結(jié)構(gòu)頻譜分析中的應(yīng)用*
劉才瑋1，吳金志1，張毅剛1,2
- 摘 要
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劉才瑋1，吳金志1，張毅剛1,2(1 北京工業(yè)大學(xué)空間結(jié)構(gòu)研究中心， 北京 100124；2 北京工業(yè)大學(xué)城市與工程安全減災(zāi)省部共建教育部重點實驗室， 北京 100124）［摘要］振動信號的頻譜分析是空間網(wǎng)格結(jié)構(gòu)模態(tài)識別及健康評定的基礎(chǔ)。通過對幾種功率譜估計方法的比較，利用最大熵譜代替?zhèn)鹘y(tǒng)經(jīng)典功率譜分析識別了環(huán)境激勵下的自振頻率，并采用AIC準(zhǔn)則確定了模型的階數(shù)。通過一個網(wǎng)架模型進(jìn)行了仿真模擬，成功地識別出了它的前6階頻率，從而驗證了最大熵譜可以用較短的振動響應(yīng)獲取較高的頻率識別精度，且能識別密集模態(tài)，適合于環(huán)境激勵下空間網(wǎng)格結(jié)構(gòu)的頻譜分析。最后將其運用到大運會主場館振動監(jiān)測系統(tǒng)中，可為類似結(jié)構(gòu)長期監(jiān)測提供參考，具有較大的工程應(yīng)用價值。［關(guān)鍵詞］空間網(wǎng)格結(jié)構(gòu)；最大熵譜；模型定階；頻譜分析；深圳大運會體育場中圖分類號：TU356 文獻(xiàn)標(biāo)識碼：A 文章編號：1002-848X(2013)04-0033-05Application of maximum entropy spectrum in the spectrum analysis of spatial lattice structuresLiu Caiwei1, Wu Jinzhi1, Zhang Yigang1, 2(1 Spatial Structures Research Center, Beijing University of Technology, Beijing 100124, China; 2 Key Lab of Urban Security and Disaster Engineering, MOE, Beijing University of Technology, Beijing 100124, China)Abstract: The spectral analysis of vibration signals is the foundation in modal identification and health assessment of spatial lattice structures. The maximum entropy method instead of the classical power spectral analysis was used to identify the natural frequency with environment excitation after the comparison of several types of power spectrum estimation methods and AIC criterion was selected to determine the order of the model. This method successfully identifies the 1～6 order frequency of a simulation space grid structures, which indicates that the maximum entropy method can be used to obtain higher vibration frequency identification accuracy with shorter response and the intensive mode and this method can be used in field of ambient excitation spectrum analysis. It has been used in the vibration observation system of the Universiade main facility, which may prove to be a reference for the long-term monitoring of the similar structures. It is valuable in the application of practical engineering.Keywords: spatial lattice structure; maximum entropy spectrum; modal order determination; spectrum analysis; Shenzhen Universiade Stadium*國家自然科學(xué)基金資助項目(51278009)。作者簡介：劉才瑋，博士研究生，Email：03150053@163.com。參考文獻(xiàn)［1］羅堯治，沈雁冰，童若飛，等. 空間結(jié)構(gòu)健康監(jiān)測與預(yù)警技術(shù)［J］. 施工技術(shù), 2009，38(3): 4-7.［2］李益華. MATLAB輔助現(xiàn)代工程數(shù)字信號處理［M］. 西安:西安電子科技大學(xué)出版社, 2010.［3］BURG J. Maximum entropy spectral analysis ［D］. Stanford: Stanford University, 1975.［4］殷祥超. 振動理論與測試技術(shù)［M］. 徐州：中國礦業(yè)大學(xué)出版社, 2007.［5］孟江. 最大熵頻譜分析與反褶積研究［D］. 西安:長安大學(xué), 2009.［6］許楠. 體育場懸挑屋蓋的脈動風(fēng)壓頻譜特性研究［D］. 哈爾濱:哈爾濱工業(yè)大學(xué), 2009.［7］陳軍. 短信號分析技術(shù)及其在故障診斷中的應(yīng)用［D］. 武漢: 武漢理工大學(xué), 2003.［8］李枝軍，李愛群，韓曉林，等. 基于最大熵譜和模糊聚類分析斜拉橋拉索索力測試與評估［J］.工程力學(xué), 2009, 26(11):88-94.［9］劉瓊祥, 張建軍, 郭滿良，等. 深圳大運中心體育場鋼屋蓋設(shè)計難點與分析［J］. 建筑結(jié)構(gòu)學(xué)報,2011,32(5):39-47.
