Modal identification based on the time–frequency domain decomposition of unknown-input dynamic tests

2013 ◽  
Vol 71 ◽  
pp. 41-50 ◽  
Author(s):  
Thien-Phu Le ◽  
Patrick Paultre
Keyword(s):  
Domain Decomposition ◽  
Frequency Domain ◽  
Modal Identification ◽  
Unknown Input ◽  
Dynamic Tests ◽  
Time Frequency ◽  
Frequency Domain Decomposition

Modal response identification of a highway bridge under traffic loads using frequency domain decomposition (FDD)

2017 ◽  
Vol 3 (2) ◽  
pp. 63
Author(s):  
Mehmet Akköse ◽  
Hugo C. Gomez ◽  
Maria Q. Feng
Keyword(s):  
Domain Decomposition ◽  
Frequency Domain ◽  
Vertical Direction ◽  
Modal Identification ◽  
Mode Shapes ◽  
Bridge Structure ◽  
Sudden Stop ◽  
Single Column ◽  
Girder Bridge ◽  
Frequency Domain Decomposition

In this study, a four-span, 224m long, post-tensioned concrete box girder bridge supported on single column piers was subject to a series of controlled vehicle tests. Bridge acceleration response datasets were used to study the effect of truck speed and a sudden stop, on the modal identification of the bridge structure. Natural frequencies and mode shapes of the bridge were determined using the frequency domain decomposition technique for all datasets. The passing of the truck rendered difficult to identify the first bridge frequency. Conversely, the vehicle tests improved the identification of higher vibration modes. This is because the truck preferentially excites the bridge vertical response, which is associated with higher modes of vibrations, especially when a sudden stop of the vehicle occurs. Thus, carefully conducted vehicle-crossing tests provide detailed information about the bridge structure dynamics in the vertical direction. However, to identify lower modes, no vehicle on the bridge is preferred.

scholarly journals Non-Parametric Operational Modal Analysis Methods in Frequency Domain: A Systematic Review

2021 ◽  
Vol 11 (1) ◽  
pp. 34-44
Author(s):  
Elsa María Cárdenas ◽  
Luis Ulises Medina
Keyword(s):  
Systematic Review ◽  
Domain Decomposition ◽  
Modal Analysis ◽  
Frequency Domain ◽  
Modal Identification ◽  
Analysis Methods ◽  
Modal Damping ◽  
Free Decay ◽  
Frequency Domain Decomposition ◽  
Non Parametric

The objective of this research is to present a systematic review of the non-parametric modal analysis methods in the frequency domain. Peak picking (PP), frequency domain decomposition (FDD), enhanced frequency domain decomposition (EFDD), and frequency–spatial domain decomposition (FSDD) are revisited and didactically illustrated by means of modal identification for a study case proposed in previous researches. Algorithm schemes are illustrated to summarize these frequency domain OMA techniques. Modal frequencies, modal damping ratios, and modal shapes are estimated using the different OMA techniques and compared to estimations obtained by the free decay (FD) method reported in previous researches. These are employed to compare the results obtained by the methods presented herein and show a very good correlation in obtaining modal frequencies and a low correlation in the case of modal damping.

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