Model updating using correlation analysis of strain frequency response function

Damage identification using the sensitivity of the dynamic characteristics of the structure of concern has been studied considerably. Among the dynamic characteristics used to locate and quantify structural damages, the frequency response function (FRF) data has the advantage of avoiding modal analysis errors. Additionally, previous studies demonstrated that strains are more sensitive to localized damages compared to displacements. So, in this study, the strain frequency response function (SFRF) data is utilized to identify structural damages using a sensitivity-based model updating approach. A pseudo-linear sensitivity equation which removes the adverse effects of incomplete measurement data is proposed. The approximation used for the sensitivity equation utilizes measured natural frequencies to reconstruct the unmeasured SFRFs. Moreover, new approaches are proposed for selecting the excitation and measurement locations for effective model updating. The efficiency of the proposed method is validated numerically through 2D truss and frame examples using incomplete and noise polluted SFRF data. Results indicate that the method can be used to accurately locate and quantify the severity of damage.

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A updating method using strain frequency response function with emphasis on local structure

Mechanical Systems and Signal Processing ◽

10.1016/j.ymssp.2018.06.025 ◽

2019 ◽

Vol 115 ◽

pp. 637-656 ◽

Cited By ~ 4

Author(s):

Ning Guo ◽

Zhichun Yang ◽

Le Wang ◽

Xin Bian

Keyword(s):

Frequency Response ◽

Response Function ◽

Local Structure ◽

Frequency Response Function ◽

Strain Frequency

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Model-updating with experimental frequency response function considering general damping

Advances in Structural Engineering ◽

10.1177/1369433217706782 ◽

2017 ◽

Vol 21 (1) ◽

pp. 82-92 ◽

Cited By ~ 5

Author(s):

Yu Hong ◽

Qianhui Pu ◽

Yang Wang ◽

Liangjun Chen ◽

Hongye Gou ◽

...

Keyword(s):

Frequency Response ◽

Response Function ◽

Frequency Response Function ◽

Model Updating ◽

Experimental Frequency

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Change of modal parameters due to crack growth in a tripod tower platform

Canadian Journal of Civil Engineering ◽

10.1139/l93-105 ◽

1993 ◽

Vol 20 (5) ◽

pp. 801-813 ◽

Cited By ~ 4

Author(s):

Yin Chen ◽

A. S. J. Swamidas

Keyword(s):

Finite Element ◽

Frequency Response ◽

Response Function ◽

Frequency Response Function ◽

Experimental Results ◽

Modal Testing ◽

Modal Parameters ◽

Response Functions ◽

Frequency Response Functions ◽

Strain Frequency

Strain gauges, along with an accelerometer and a linear variable displacement transducer, were used in the modal testing to detect a crack in a tripod tower platform structure model. The experimental results showed that the frequency response function of the strain gauge located near the crack had the most sensitivity to cracking. It was observed that the amplitude of the strain frequency response function at resonant points had large changes (around 60% when the crack became a through-thickness crack) when the crack grew in size. By monitoring the change of modal parameters, especially the amplitude of the strain frequency response function near the critical area, it would be very easy to detect the damage that occurs in offshore structures. A numerical computation of the frequency response functions using finite element method was also performed and compared with the experimental results. A good consistency between these two sets of results has been found. All the calculations required for the experimental modal parameters and the finite element analysis were carried out using the computer program SDRC-IDEAS. Key words: modal testing, cracking, strain–displacement–acceleration frequency response functions, frequency–damping–amplitude changes.

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