Evaluation of paint coating thickness variations based on pulsed Infrared thermography laser technique

Defect inspection based on eddy current pulsed thermography (ECPT) technique is a research focus in non-destructive testing (NDT) area. In this paper, a novel defect feature extraction approach for automated defect analyzing based on ECPT has been proposed to improve the feature quality of defects. This approach can separate defect features from background interference such as noises and heating coil. The highlights of this algorithm are mainly on the following three aspects: 1) the physical meaning of initial data is combined with the mathematical algorithm to improve the interpretability of results; 2) local sparse component evaluation based on principal components analysis can reserve more significant defect features; and 3) a two-phased fusion criterion for feature integration is defined to improve the quality of defect features. Two typical steel specimens are utilized to testify the validity of the proposed approach. Compared with other three feature extraction algorithms in ECPT, the proposed approach can reserve more useful defect features and suppress more background interferences.INDEX TERMS Non-destructive testing, eddy current, thermography, infrared image analysis, feature extraction, defect enhancement.

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“…Many researchers have researched defect feature extraction approach in ECPT for defect inspection [8]- [10]. He etc.…”

Section: Introductionmentioning

confidence: 99%

Improvement of Defect Feature Extraction in Eddy Current Pulsed Thermography

2019

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“…Pulsed thermography can be applied to the identification of subsurface defects, their depths and sizes in metals, ceramics and composite materials [3][4][5][6] while mathematical models can provide a deeper understanding of this process and obtain optimal parameters for the experimental investigations. In [7] numerical simulations were performed to obtain optimal values of excitation parameters with respect to the evaluation of the paint coating thickness. A numerical model of the pulsed thermography for heterogeneous materials has been developed in [8] on the base of the finite volume method.…”

Section: Introductionmentioning

confidence: 99%

Numerical simulation of subsurface defect identification by pulsed thermography and improvement of this technique for noisy data

Plekhov

Kostina

Aizikovich

2019

Frattura Ed Integrità Strutturale

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Pulsed thermography is an active non-destructive technique which uses optical excitation source to stimulate heating of the object under investigation. This work is devoted to the simulation of the pulsed thermography method in a steel plate with a ceramic coating containing artificial defects of various depths and sizes. The simulation has been carried out on the base of a model which takes into account complex heat exchange of the sample with the surrounding by convection, conduction and radiation. Comparison of the temperature contrast with the experimental data has shown that the results are in a good qualitative and quantitative agreement in all stages of the cooling process. Due to the fact that the temperature contrast is often susceptible to surface noise of various nature the Kalman-based signal processing technique was developed. The comparative analysis has shown that the proposed filtration technique provides a better signal-to-noise ratio in comparison to the considered well-known techniques of signal reconstruction when proper calibration of the filtration parameters is carried out.

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“…A paint layer is essential for the metallic structure and widely used throughout the industry to protect the metallic structures from the various exterior conditions such as humidity, direct sunlight, and salty conditions [1][2][3]. An improper paint thickness can cause the corrosion and section loss of the metallic structures [4,5], and the local damage on the metallic structures can cause a stress concentration, and accelerate the structural deterioration [6,7].…”

Section: Introductionmentioning

confidence: 99%

“…Mezghani et al proposes a laser thermography system to inspect a paint thickness in a single point with a non-contact manner [1]. However, numerous time is required to visualize paint thickness distribution in wide area with integrating test results acquired from the multiple inspections.…”

Section: Introductionmentioning

confidence: 99%

Reference-free Coating Thickness Quantification using Laser Thermography under Various Exterior Temperature Conditions

Hwang¹,

Park²,

Jin³

et al. 2018

Proceedings of the 2018 International Conference on Quantitative InfraRed Thermography

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This paper presents a reference-free paint-thickness visualization method using thermography. When thermalwaves generated by a continuous-wave laser are applied to a paint-surface, the thermal-waves propagate through the paint-layer and the resultant thermal-waves are measured by an infrared camera. The propagating characteristics of thermal-waves through the paint-layer are altered from the changes on the thickness of paint-layer. Accordingly, the alternation can be mapped as the paint-thickness regardless of varying exterior temperature conditions by analysing the phase and amplitude of the thermal-waves acquired by the infrared camera, and the accuracy of the thickness quantification can be further enhanced by additional image processes.

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Evaluation of paint coating thickness variations based on pulsed Infrared thermography laser technique

Cited by 23 publications

References 27 publications

Improvement of Defect Feature Extraction in Eddy Current Pulsed Thermography

Improvement of Defect Feature Extraction in Eddy Current Pulsed Thermography

Numerical simulation of subsurface defect identification by pulsed thermography and improvement of this technique for noisy data

Reference-free Coating Thickness Quantification using Laser Thermography under Various Exterior Temperature Conditions

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