Improved VMD and its application in instantaneous frequency identification of seismic responses of time-varying structures

被引：0
|
作者：
Wang Y.-N. [1 ]
Shang X.-Q. [1 ]
Huang T.-L. [1 ]
机构：
[1] School of Civil Engineering, Central South University, Changsha
来源：
Zhendong Gongcheng Xuebao/Journal of Vibration Engineering | 2024年 / 37卷 / 03期
关键词：
instantaneous frequency identification; seismic excitation; shaking table test; time-varying frame structures; VMD;
D O I：
10.16385/j.cnki.issn.1004-4523.2024.03.005
中图分类号：
学科分类号：
摘要：
Under the action of strong seismic excitations, structures exhibit time-varying dynamic characteristics due to damage. Variational mode decomposition(VMD)can be used to analyze the instantaneous frequency variation of structural seismic responses and reveal the damage condition of structures during earthquake. When VMD is adopted for decomposing the non-stationary responses, there exists the problem of mode aliasing due to the artificially presetting the number of decomposed modes K and the quadratic penalty factor α. Aiming at solving this problem, an improved variational mode decomposition (IVMD) algorithm is proposed in this study, which, combined with Hilbert transform (HT), can more accurately identify the instantaneous frequencies of time-varying structures under non-stationary seismic excitations. The multiple signal classification(MUSIC)algorithm is used to determine the number of decomposition modes K. The comprehensive objective function is constructed based on the overall orthogonal coefficient and energy ratio coefficient, and the slap swarm algorithm (SSA) is used to optimize and determine the optimal quadratic penalty factor α. Based on the optimized parameters K and α, IVMD-HT is used to identify the instantaneous frequency of time-varying structures from the seismic responses. A simulated signal and the seismic responses of a 4-layer time-varying frame structure show that the accuracy of identified instantaneous frequencies by using the IVMD algorithm is higher than the identified ones by using the VMD algorithm. The feasibility of the proposed method is verified by using shaking table test data of a 12-story reinforced concrete frame structure model. © 2024 Nanjing University of Aeronautics an Astronautics. All rights reserved.
引用
收藏
页码：402 / 413
页数：11
相关论文
共 27 条
  • [1] Xin Y, Li J, Hao H., Enhanced vibration decomposition method based on multisynchrosqueezing transform and analytical mode decomposition[J], Structural Control and Health Monitoring, 28, 6, (2021)
  • [2] Loh C H, Chao S H, Weng J H, Et al., Application of subspace identification technique to long-term seismic response monitoring of structures[J], Earthquake Engineering & Structural Dynamics, 44, 3, pp. 385-402, (2015)
  • [3] Ni Y C, Zhang F L., Fast Bayesian frequency domain modal identification from seismic response data[J], Computers & Structures, 212, pp. 225-235, (2019)
  • [4] Ghahari S F, Abazarsa F, Ghannad M A, Et al., Response-only modal identification of structures using strong motion data[J], Earthquake Engineering & Structural Dynamics, 42, 8, pp. 1221-1242, (2013)
  • [5] Guo Y L, Kareem A., System identification through nonstationary data using time-frequency blind source separation[J], Journal of Sound and Vibration, 371, pp. 110-131, (2016)
  • [6] Loh C H, Chen J D., Tracking modal parameters from building seismic response data using recursive subspace identification algorithm[J], Earthquake Engineering & Structural Dynamics, 46, 13, pp. 2163-2183, (2017)
  • [7] Pioldi F, Rizzi E., Earthquake-induced structural response output-only identification by two different Operational Modal Analysis techniques[J], Earthquake Engineering & Structural Dynamics, 47, 1, pp. 257-264, (2018)
  • [8] Chen W H, Hseuh W, Loh K J, Et al., Damage evaluation of seismic response of structure through time-frequency analysis technique[J], Structural Monitoring and Maintenance, 9, 2, pp. 107-127, (2022)
  • [9] Fan Haitao, He Yibin, Zhou Xuhong, Structural damage detection study based on Hilbert-Huang transform, Journal of Building Structure, 27, 6, pp. 114-122, (2006)
  • [10] Shi Chunxiang, Luo Qifeng, Shi Weixing, Hilbert-Huang transform based approach for structural damage detection, Journal of Tongji University(Natural Science), 33, 1, pp. 16-20, (2005)
123