Vibration Technique for Locating Delamination in a Composite Beam

Ratcliffe, Colin P.; Bagaria, William J.

doi:10.2514/2.482

Cited by 133 publications

(49 citation statements)

References 10 publications

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“…in which, f z i ð Þ ¼ 1:862z 2 i À 3:95z 3 i þ 16:375z 4 i À 37:226z 5 i þ 76:81z 6 i À 126z 7 i þ 172z 8 i À 143:97z 9 i þ 66:56z 10 i , and zi is the ratio of the ith crack depth to the height of the cross section h.…”

Section: Simulated Dynamic Deflections Of Cracked Bridgesmentioning

confidence: 99%

“…Changes in dynamic characteristics of a linear structural system have been widely used to detect bridge damage and identify structural properties. For example, each crack on a bridge deck or girder introduces local flexibility in the bridge superstructure [4][5][6], and it can be detected with a change of natural frequency and/or mode shape [7][8][9][10][11][12][13][14][15][16][17][18][19][20][21]. Lee [22] identified cracks by solving an inverse problem for crack detection and localization using the Newton-Raphson method and the singular value decomposition method, depending on vibration amplitudes.…”

Section: Introductionmentioning

confidence: 99%

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A moving-window least squares fitting method for crack detection and rigidity identification of multispan bridges

Wang

Chen

2011

Struct. Control Health Monit.

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SUMMARY In this study, a moving‐window least squares fitting method is proposed for rapid identification of cracks and flexural rigidities in multispan bridges. First, the dynamic deflections of a continuous bridge were locally measured under a dynamic point load. Their integrations over time, referred to as ‘integration‐over‐time deflections’, were used to derive ‘integration‐over‐time slopes’. These virtually static measurements over a short segment of the bridge were then fitted into a cubic curve in the least squares sense. Finally, the coefficient of the square term of the fitted curve was used to determine both the magnitude and location of local flexibility because of cracking and/or changing in flexural rigidity of the bridge. For multispan continuous bridges, an iterative procedure was developed to ensure that the end moments of various spans are compatible with the identified cracks and rigidity changes. To illustrate the proposed method, prismatic girder bridges with multiple cracks of various depths or non‐prismatic girder bridges were analyzed. Sensitivity analysis was conducted on the effects of weighting factor, noise level, load type, window length, and bridge discretization. Numerical results demonstrated that the proposed method can accurately detect cracks and identify the change in flexural rigidity. The five‐point equally weighted algorithm is recommended for practical applications. The spacing of two discernible cracks is equal to the window length. The identified results are insensitive to noise because of integration of the dynamic measurements. Copyright © 2011 John Wiley & Sons, Ltd.

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Section: Simulated Dynamic Deflections Of Cracked Bridgesmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

A moving-window least squares fitting method for crack detection and rigidity identification of multispan bridges

Wang

Chen

2011

Struct. Control Health Monit.

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“…However, the major drawback of these methods is a need for the data of the healthy structure, which sometimes can be difficult or even impossible to obtain. This issue is solved either by using finite element model to simulate the dynamic response of the healthy structure or by employing gapped smoothing techniques or smoothing element analysis to generate a smoothed surface of the mode shape curvature obtained from the damaged structure, thus simulating the healthy state of a structure.…”

Section: Introductionmentioning

confidence: 99%

Mode shape-based damage detection in plate structure without baseline data

Ručevskis

Janeliukštis

Akishin

et al. 2016

Struct. Control Health Monit.

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In this paper, a mode shape curvature-based method for detection and localization of damage in plate-like structures is described. The proposed algorithm requires only the mode shape curvature data of the damaged structure. The damage index is defined as the absolute difference between the measured curvature of the damaged structure and the smoothed polynomial representing the curvature of the healthy structure. To examine the advantages and limitations of the proposed method, several sets of numerical simulations are carried out. Simulated test cases considering different levels of damage severity, measurement noise and sensor sparsity are studied to evaluate the robustness of the method under the noisy experimental data and limited sensor data. Applicability and effectiveness of the proposed damage detection method are further demonstrated experimentally on an aluminium plate containing mill-cut damage. The modal frequencies and the corresponding mode shapes are obtained via finite element models for numerical simulations and by using a scanning laser vibrometer for the experimental study. Copyright

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“…Valdes and Soutis [6] conducted experiments to study the effects of delamination in laminated beams on the changes in modal frequencies. Racliffe and Bagaria [7] used curvature mode shapes to locate delaminations in a composite beam. Wei et al [8] evaluated delamination of multilayer composite plates using model-based neural networks.…”

Section: Introductionmentioning

confidence: 99%

Delamination Detection of Reinforced Concrete Decks Using Modal Identification

2012

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This study addressed delamination detection of concrete slabs by analyzing global dynamic responses of structures. Both numerical and experimental studies are presented. In the numerical examples, delaminations with different sizes and locations were introduced into a concrete slab; the effects of presence, sizes, and locations of delaminations on the modal frequencies and mode shapes of the concrete slab under various support conditions were studied. In the experimental study, four concrete deck specimens with different delamination sizes were constructed, and experimental tests were conducted. Traditional peak-picking, frequency domain decomposition, and stochastic subspace identification methods were applied to the modal identification from dynamic response measurements. The modal parameters identified by these three methods correlated well. The changes in modal frequencies, damping ratios, and mode shapes that were extracted from the dynamic measurements were investigated and correlated to the actual delaminations and can indicate presence and severity of delamination. Finite element (FE) models of reinforced concrete decks with different delamination sizes and locations were established. The modal parameters computed from the FE models were compared to those obtained from the laboratory specimens, and the FE models were validated. The delamination detection approach was proved to be effective for concrete decks on beams.

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Vibration Technique for Locating Delamination in a Composite Beam

Cited by 133 publications

References 10 publications

A moving-window least squares fitting method for crack detection and rigidity identification of multispan bridges

A moving-window least squares fitting method for crack detection and rigidity identification of multispan bridges

Mode shape-based damage detection in plate structure without baseline data

Delamination Detection of Reinforced Concrete Decks Using Modal Identification

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