On the study of element modal strain energy sensitivity for damage detection of functionally graded beams

This paper presents a multistage multipass method to identify the damage location of a continuous bridge from the response of a vehicle moving on the rough road surface of the bridge. The vehicle runs over the bridge several times at different velocities and the corresponding responses of the vehicle can be obtained. The vertical accelerations of the vehicle running on the intact and damaged bridges are used for identification. The multistage damage detection method is implemented by the modal strain energy based method and genetic algorithm. The modal strain energy based method estimates the damage location by calculating a damage indicator from the frequencies extracted from the vehicle responses of both the intact and damaged states of the bridge. At the second stage, the identification problem is transformed into a global optimization problem and is solved by genetic algorithm techniques. For each pass of the vehicle, the method can identify the location of the damage until it is determined with acceptable accuracy. A two-span continuous bridge is used to verify the method. The numerical results show that this method can identify the location of damage reasonably well.

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An efficient modal strain energy-based damage detection for laminated composite plates

Advanced Composite Materials ◽

10.1080/09243046.2017.1301069 ◽

2017 ◽

Vol 27 (2) ◽

pp. 147-162 ◽

Cited By ~ 8

Author(s):

Mohammad-Reza Ashory ◽

Ahmad Ghasemi-Ghalebahman ◽

Mohammad-Javad Kokabi

Keyword(s):

Damage Detection ◽

Strain Energy ◽

Laminated Composite ◽

Composite Plates ◽

Laminated Composite Plates ◽

Modal Strain Energy

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Study on Damage Location of Spatial Structures Based on Wavelet Analysis of Model Strain Energy

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.639-640.1033 ◽

2013 ◽

Vol 639-640 ◽

pp. 1033-1037

Author(s):

Yong Mei Li ◽

Bing Zhou ◽

Guo Fu Sun ◽

Bo Yan Yang

Keyword(s):

Wavelet Analysis ◽

Damage Detection ◽

Structural Damage ◽

Strain Energy ◽

Damage Identification ◽

Damage Index ◽

Structural Damage Detection ◽

Modal Strain Energy ◽

Wavelet Method ◽

Long Span

The research to identify and locate the damage to the engineering structure mainly aimed at some simple structure forms before, such as beam and framework. Damage shows changes of local characteristics of the signal, while wavelet analysis can reflect local damage traits of the signal in time domain and frequency domain. For confirming the validity and applicability of structural damage identification methods, wavelet analysis is used to spatial structural damage detection. The wavelet analysis technique provides new ideas and methods of spatial steel structural damage detection. Based on the theory of wavelet singularity detection，with the injury signal of modal strain energy as structural damage index，the mixing of the modal strain energy and wavelet method to identify and locate the damage to the spatial structure is considered. The multiplicity of the bars and nodes can be taken into account, and take the destructive and nondestructive modal strain energy of Kiewitt-type reticulated shell with 40m span as an example of numerical simulation，the original damage signal and the damage signal after wavelet transformation is compared. The location of the declining stiffness identified by the maximum of wavelet coefficients，analyzed as signal by db1 wavelet，and calculate the graph relation between coefficients of the wavelets and the damage to the structure by discrete or continuous wavelet transform, and also check the accuracy degree of this method with every damage case. Finally，the conclusion is drawn that the modal strain energy and wavelet method to identify and locate the damage to the long span reticulated shell is practical, effective and accurate, that the present method as a reliable and practical way can be adopted to detect the single and several locations of damage in structures.

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