Stochastic System Identification for Operational Modal Analysis: A Review

2001 ◽  
Vol 123 (4) ◽  
pp. 659-667 ◽  
Author(s):  
Bart Peeters ◽  
Guido De Roeck
Keyword(s):  
System Identification ◽  
Stochastic System ◽  
Instrumental Variable ◽  
Subspace Identification ◽  
Response Functions ◽  
Impulse Responses ◽  
Identification Methods ◽  
Operational Conditions ◽  
Stochastic Subspace Identification ◽  
Output Only

This paper reviews stochastic system identification methods that have been used to estimate the modal parameters of vibrating structures in operational conditions. It is found that many classical input-output methods have an output-only counterpart. For instance, the Complex Mode Indication Function (CMIF) can be applied both to Frequency Response Functions and output power and cross spectra. The Polyreference Time Domain (PTD) method applied to impulse responses is similar to the Instrumental Variable (IV) method applied to output covariances. The Eigensystem Realization Algorithm (ERA) is equivalent to stochastic subspace identification.

scholarly journals ESTIMATION OF STRUCTURAL DYNAMICS OF A MODEL BOOM OF DRAGLINE DRE-23 BY OUTPUT-ONLY SYSTEM IDENTIFICATION METHODS

2011 ◽  
Author(s):  
Zakir Faruquee ◽  
Hal Gurgenci
Keyword(s):  
System Identification ◽  
Modal Analysis ◽  
Damping Ratio ◽  
Canonical Variate ◽  
Identification Methods ◽  
Analysis Methods ◽  
Electrodynamic Shaker ◽  
Simulated Field ◽  
Output Only ◽  
Frequency Domain Decomposition

Two output -only system identification methods namely Canonical Variate Analysis (CVA) and Frequency Domain Decomposition (FDD) were used to estimate the dynamics (Mode shape, natural frequency and damping ratio) of the model boom of the dragline DRE 23. The boom was excited separately with an impulse hammer and with an electrodynamic shaker with chirp, random and simulated field excitations. In all cases, the excitations as well as the responses of the model boom were measured. The dynamics were obtained from the response measurements using Output-Only methods as well as from both the excitations and responses using conventional modal analysis methods. In all cases, the estimations of the dynamics by Output-Only methods were comparable if not better than those estimates obtained by the convention modal analysis methods.

scholarly journals OUTPUT-ONLY MODAL IDENTIFICATION OF TENSEGRITY STRUCTURES

2016 ◽  
Vol 8 (2) ◽  
pp. 52-64 ◽  
Author(s):  
Miniar Attig ◽  
Maher Abdelghani ◽  
Nabil ben Kahla
Keyword(s):  
Natural Frequencies ◽  
Modal Identification ◽  
Mode Shapes ◽  
Subspace Identification ◽  
Balanced Realization ◽  
Stochastic Subspace Identification ◽  
Tensegrity Systems ◽  
Stabilization Diagram ◽  
Subspace Algorithms ◽  
Output Only

Tensegrity systems are a special class of spatial reticulated structures that are composed of struts in compression and cables in tension. In this paper, the performance of stochastic subspace algorithms for modal identification of complex tensegrity systems is investigated. A sub-class algorithm of the Stochastic Subspace Identification family: the Balanced Realization Algorithm is investigated for modal identification of a tripod simplex structure and a Geiger dome. The presented algorithm is combined with a stabilization diagram with combined criteria (frequency, damping and mode shapes). It is shown that although the studied structures present closely spaced modes, the Balanced Realization Algorithm performs well and guarantees separation between closely-spaced natural frequencies. Modal identification results are validated through comparisons of the correlations (empirical vs. model based) showing effectiveness of the proposed methodology.

Experimental Modal Analysis of Jacket-Type Platforms Using Data-Driven Stochastic Subspace Identification Method

2012 ◽  
Author(s):  
Junfeng Xin ◽  
Sau-Lon James Hu ◽  
Huajun Li
Keyword(s):  
White Noise ◽  
Impact Loading ◽  
Modal Identification ◽  
Data Driven ◽  
Subspace Identification ◽  
Stochastic Subspace Identification ◽  
Gaussian White Noise Process ◽  
Using Data ◽  
Output Only ◽  
The Impact

Employing efficient techniques to accurately identify the modal parameters of new and aging offshore structures has been of interest to the offshore industry for decades. Early methods of modal identification were developed for the frequency domain. The new trend is to employ either input-output or output-only time-domain modal identification methods. Under the assumption that the excitation input is a zero-mean Gaussian white noise process, a modern output-only method that allows direct application to the response time series is the data-driven stochastic subspace identification (SSI-data) method. The main objective of this paper is to evaluate the performance of the SSI-data method using the test data measured from a physical model of a realistic offshore jacket-type platform. Response acceleration data associated with three different excitation mechanisms are investigated: impact loading, step relaxation and white noise ground motion. Although the SSI-data method has been theoretically developed, and often perceived to be only valid, for the ambient noise testing environment, it is shown in this study that the SSI-data method also performs well using data from either the impact loading or step relaxation tests.

Stay Force Estimation in Cable-Stayed Bridges Using Stochastic Subspace Identification Methods

2017 ◽  
Vol 22 (9) ◽  
pp. 04017055 ◽  
Author(s):  
Seyed Ehsan Haji Agha Mohammad Zarbaf ◽  
Mehdi Norouzi ◽  
Randall J. Allemang ◽  
Victor J. Hunt ◽  
Arthur Helmicki ◽  
...  
Keyword(s):  
Subspace Identification ◽  
Force Estimation ◽  
Identification Methods ◽  
Stochastic Subspace Identification ◽  
Cable Stayed Bridges
Sign in / Sign up

Export Citation Format

Share Document