水利学报
水利學報
수리학보
2014年
8期
958-966
,共9页
水工结构%模态识别%水口混凝土重力坝%Hilbert-Huang变换%自然激励技术
水工結構%模態識彆%水口混凝土重力壩%Hilbert-Huang變換%自然激勵技術
수공결구%모태식별%수구혼응토중력패%Hilbert-Huang변환%자연격려기술
hydraulic structure%modal identification%Shuikou concrete gravity dam%Hilbert-Huang trans-form%natural excitation technique
在自然激励技术和 Hilbert-huang变换相结合的基础上，利用水口水电站的强震监测资料，对水口混凝土重力坝进行模态参数识别。发展了将带通滤波技术与该时频域模态识别技术相结合的方法，有效地避免了信号分解时所产生的频率混杂现象，从而提高了参数识别精度和可靠性。首先利用结构动力学的简例验证了该方法的正确性，然后将该方法应用于混凝土重力坝的模态识别问题。计算结果表明，采用本文的时频域 HHT+NExT方法识别的重力坝模态频率稍大于传统的频域峰值点拾取法和时域 ARX法，与有限元计算结果更为接近，识别的阻尼比也稍大于峰值法和 ARX法，略小于水工抗震设计规范规定取值范围5%～10%的下限5%。
在自然激勵技術和 Hilbert-huang變換相結閤的基礎上，利用水口水電站的彊震鑑測資料，對水口混凝土重力壩進行模態參數識彆。髮展瞭將帶通濾波技術與該時頻域模態識彆技術相結閤的方法，有效地避免瞭信號分解時所產生的頻率混雜現象，從而提高瞭參數識彆精度和可靠性。首先利用結構動力學的簡例驗證瞭該方法的正確性，然後將該方法應用于混凝土重力壩的模態識彆問題。計算結果錶明，採用本文的時頻域 HHT+NExT方法識彆的重力壩模態頻率稍大于傳統的頻域峰值點拾取法和時域 ARX法，與有限元計算結果更為接近，識彆的阻尼比也稍大于峰值法和 ARX法，略小于水工抗震設計規範規定取值範圍5%～10%的下限5%。
재자연격려기술화 Hilbert-huang변환상결합적기출상，이용수구수전참적강진감측자료，대수구혼응토중력패진행모태삼수식별。발전료장대통려파기술여해시빈역모태식별기술상결합적방법，유효지피면료신호분해시소산생적빈솔혼잡현상，종이제고료삼수식별정도화가고성。수선이용결구동역학적간례험증료해방법적정학성，연후장해방법응용우혼응토중력패적모태식별문제。계산결과표명，채용본문적시빈역 HHT+NExT방법식별적중력패모태빈솔초대우전통적빈역봉치점습취법화시역 ARX법，여유한원계산결과경위접근，식별적조니비야초대우봉치법화 ARX법，략소우수공항진설계규범규정취치범위5%～10%적하한5%。
Modal identification of the Shuikou concrete gravity dam has been conducted based on natural ex-citation technique and Hilbert-Huang transform under four different seismic excitations on it. A new ap-proach is proposed by bandpass filtering technology combining with the modal identification method, which avoids the phenomenon of frequency mixed effectively during the signal decomposition, thus improving the accuracy and reliability of the modal parameter identification. Firstly,a simple example of structural dynam-ics was used to verify the correctness of the method, and then this method was used for concrete gravity dam modal parameter identification for the first time. The results show that the frequencies identified by HHT+NExT are slightly larger than the result of the peak-picking method and ARX model, and close to the results of FEM. Damping ratios identified by HHT+NExT are also somewhat larger than the results of the peak-picking method and ARX model, and meanwhile, they are slightly less than the design specifica-tion ranges namely between 5% ~ 10% of the lower limit of 5% in specifications for seismic design of hy-draulic structures.
