Ultrasonic system for imaging delaminations in composite materials

Lloyd, Peter

doi:10.1016/0041-624x(89)90003-6

Cited by 15 publications

(9 citation statements)

References 3 publications

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“…Kapur et al [28] introduced an entropy-based thresholding method. The threshold ܶ is set to the 8 intensity level ݆ at which the entropy formulation, 9 In which the threshold ܶ estimated using the Otsu's method lies in the midway between the means of 1 the two classes (foreground and background).…”

Section: Image Segmentation Based On Thresholding 16 17mentioning

confidence: 99%

Automated Quality Characterization for Composites Using Hybrid Ultrasonic Imaging Techniques

Sun

Chong

Tavakoli

et al. 2018

Research in Nondestructive Evaluation

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An enhanced technique using image processing has been developed for automated ultrasonic 10 inspection of composite materials, such as glass/carbon-fibre-reinforced polymer (GFRP or CFRP), to 11 ascertain their structural healthiness. The proposed technique is capable of identifying the abnormality 12 features buried in the composite by image filtering and segmentation applied to ultrasonic C-Scan 13 images. This work presents results performed on two composite samples with simulated delamination 14 defects. A local gating scheme is applied to raw A-Scan data for improved contrast between defective 15 and healthy regions in the produced C-Scan image. In this test campaign, different filtering and 16 thresholding algorithms are evaluated and compared in term of their effectiveness on defect 17 identification. The accuracies of less than 3 mm and 1.11 mm were attained for the defect size and 18 depth respectively. The results demonstrates the applicability of the proposed technique for accurate 19 defect localization and characterization of composite materials.

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Section: Image Segmentation Based On Thresholding 16 17mentioning

confidence: 99%

Automated Quality Characterization for Composites Using Hybrid Ultrasonic Imaging Techniques

Sun

Chong

Tavakoli

et al. 2018

Research in Nondestructive Evaluation

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“…A variety of non-destructive testing methods are utilised for post-fabrication and in-service inspection [7][8][9]. Ultrasonic C-scans have been found to provide very sensitive measurements of the location and size of damage, especially for delaminations [10][11][12]. Ultrasound has been demonstrated to detect and map out-of-plane ply wrinkling, in-plane fibre orientation and porosity in composites [13].…”

Section: Introductionmentioning

confidence: 98%

Edge-illumination X-ray dark-field imaging for visualising defects in composite structures

Endrizzi

Murat

Fromme

et al. 2015

Composite Structures

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a b s t r a c tLow velocity impact can lead to barely visible and difficult to detect damage such as fibre and matrix breakage or delaminations in composite structures. Drop-weight impact damage in a cross-ply carbon fibre laminate plate was characterised using ultrasonic C-scan measurements. This was compared to the results provided by a novel X-ray imaging technique based on the detection of phase effects, which can be implemented with conventional equipment. Three representations of the sample are provided: absorption, differential phase and dark-field. The latter is of particular interest to detect cracks and voids of dimensions that are smaller than the spatial resolution of the imaging system. The ultrasonic C-scan showed a large delamination and additional damage along the fibre directions. The damage along the fibre directions and other small scale defects were detected from the X-ray imaging. As the system is sensitive to phase effects along one direction at a time, the acquisition of an additional scan, rotating the sample 90°around the beam axis, provides information in both fibre directions. These two techniques enable access to a set of complementary information, across different length scales, which can be useful in the characterisation of the defects occurring in composite structures.

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“…Experimental testing will be required to examine the effect of delamination orientation on propagation behavior and the error associated with the assumptions of the model. 4,90] were considered in this investigation, where the a subscript indicates anti-symmetric ply stacking with respect to the tube mid-surface. The lamina were all of equal thickness, the total thickness of each tube was 1.27 mm (50 mil), and the thickness to wall midplane radius ratio was 1/10.…”

Section: Physical Problem Description and Modelingmentioning

confidence: 99%

“…These include noise resulting from scattering of the interrogating waves with internal structure (Le. fibers, porosity and "good" laminations) stemming from the requirement that high frequency waves be used for thin walled specimens, relatively long scanning times, and the unsuitability of immersion testing for many applications [4,5]. An additional artifact of this propagation direction, is the insensitivity of such waves to the longitudinal modulus in the axial direction.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Analysis of Detection of Delaminations in Fiber Reinforced Composite Tubes Using Axially Symmetric Guided Waves

Kohl

Rogers

Datta

1993

Review of Progress in Quantitative Nondestructive Evaluation

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Ultrasonic system for imaging delaminations in composite materials

Cited by 15 publications

References 3 publications

Automated Quality Characterization for Composites Using Hybrid Ultrasonic Imaging Techniques

Automated Quality Characterization for Composites Using Hybrid Ultrasonic Imaging Techniques

Edge-illumination X-ray dark-field imaging for visualising defects in composite structures

Analysis of Detection of Delaminations in Fiber Reinforced Composite Tubes Using Axially Symmetric Guided Waves

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