Spot Weld Inspections Using Active Thermography

Verspeek, Simon; Ribbens, Bart; Maldague, Xavier; Steenackers, Gunther

doi:10.3390/app12115668

Cited by 10 publications

(6 citation statements)

References 14 publications

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“…Nonuniform heating of a sample can be attributed to the presence of inner material flaws, such as delamination and lack of adhesive. These flaws result in the manifestation of hotter or cooler regions visible in the temperature distribution on the sample's surface [36][37][38][39][40].…”

Section: Active Thermography Methodsmentioning

confidence: 99%

Defect Detection in CFRP Concrete Reinforcement Using the Microwave Infrared Thermography (MIRT) Method—A Numerical Modeling and Experimental Approach

et al. 2023

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This research paper presents the application of the microwave infrared thermography (MIRT) technique for the purpose of detecting and characterizing defects in the carbon-fiber-reinforced polymer (CFRP) composite reinforcement of concrete specimens. Initially, a numerical model was constructed, which consisted of a broadband pyramidal horn antenna and the specimen. The present study investigated the application of a 360 W power system that operated at a frequency of 2.4 GHz, specifically focusing on two different operational modes: continuous and modulated. The specimen being examined consisted of a solid concrete slab that was coated with an adhesive layer, which was then overlaid with a layer of CFRP. Within the adhesive layer, at the interface between the concrete and CFRP, there was a defect in the form of an air gap. The study examined three distinct scenarios: a sample without any defects, a sample with a defect positioned at the center, and a sample with a defect positioned outside the center. The subsequent stage of the investigation incorporated experimental verification of the numerical modeling results. The experiment involved the utilization of two concrete specimens reinforced using CFRP, one without any defects and the other with a defect. Numerical modeling was used in this study to analyze the phenomenon of microwave heating in complex structures. The objective was to evaluate the selected antenna geometry and determine the optimal experimental configuration. Subsequently, these findings were experimentally validated. The observations conducted during the heating phase were particularly noteworthy, as they differed from previous studies that only performed observation of the sample after the heating phase. The results show that MIRT has the potential to be utilized as a method for identifying defects in concrete structures that are reinforced with CFRP.

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Section: Active Thermography Methodsmentioning

confidence: 99%

Defect Detection in CFRP Concrete Reinforcement Using the Microwave Infrared Thermography (MIRT) Method—A Numerical Modeling and Experimental Approach

et al. 2023

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“…PT has been extensively applied to a variety of materials, such as CFRP [19] and glass fiber reinforced materials [24]. In [25], different active thermography methods, including pulsed thermography and lock-in thermography, are investigated for the inspection of spot welds. The study also evaluates different heating methods and data post-processing approaches to identify the optimal combination.…”

Section: Related Work 21 Pulsed Thermography Technologymentioning

confidence: 99%

Pulsed Thermography Dataset for Training Deep Learning Models

Wei¹,

Osman²,

Valeske³

et al. 2023

Preprint

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Pulsed thermography is a vital technique in the nondestructive evaluation field. However, its data analysis can be complex and requires skilled experts. Advances in deep learning have yielded exceptional results, including image segmentation. Therefore, many efforts have been made to apply deep learning methods to data processing for nondestructive evaluation. Despite this, there is currently no public Pulsed thermographic dataset available for evaluating various spatial-temporal deep methods of segmenting pulsed thermographic data. This article aims to provide such a dataset and assess the performance of commonly used deep learning-based instance segmentation models on it. Additionally, the impact of the number of frames and data transformations on model performance is examined. The findings suggest that suitable preprocessing methods can effectively reduce the data size without compromising the deep models’ performance.

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“…The destructive methods measure the remaining weld nugget in two perpendicular directions and calculate the shear stress that destroys the joint. Non-destructive methods for testing spot welded joints include ultrasonic [15], radiographic [16], magnetic [17,18] and thermographic methods [19,20]. Vision systems for evaluating spot welded joints and machine learning methods applied during their manufacturing on the production line have also been proposed [21][22][23].…”

Section: Introductionmentioning

confidence: 99%

Inspection of Spot Welded Joints with the Use of the Ultrasonic Surface Wave

Ulbrich,

Psuj,

Wypych

et al. 2023

Materials

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Spot welded joints play a crucial role in the construction of modern automobiles, serving as a vital method for enhancing the structural integrity, strength, and durability of the vehicle body. Taking into account spot welding process in automotive bodies, numerous defects can arise, such as insufficient weld nugget diameter. It may have evident influence on vehicle operation or even contribute to accidents on the road. Hence, there is a need for non-invasive methods that allow to assess the quality of the spot welds without compromising their structural integrity and characteristics. Thus, this study describes a novel method for assessing spot welded joints using ultrasound technology. The usage of ultrasonic surface waves is the main component of the proposed advancement. The study employed ultrasonic transducers operating at a frequency of 10 MHz and a specially designed setup for testing various spot welded samples. The parameters of the spot welding procedure and the size of the weld nugget caused differences in the ultrasonic surface waveforms that were recorded during experiments. One of the indicators of weld quality was the amplitude of the ultrasonic pulse. For low quality spot welds, the amplitude amounted to around 25% of the maximum value when using single-sided transducers. Conversely, for high-quality welds an amplitude of 90% was achieved. Depending on the size of the weld nugget, a larger or smaller amount of wave energy is transferred, which results in a smaller or larger amplitude of the ultrasonic pulse. Comparable results were obtained when employing transducers on both sides of the tested joint, as an amplitude ranging from 13% for inferior welds to 97% for superior ones was observed. This research confirmed the feasibility of employing surface waves to assess the diameter of the weld nugget accurately.

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Spot Weld Inspections Using Active Thermography

Cited by 10 publications

References 14 publications

Defect Detection in CFRP Concrete Reinforcement Using the Microwave Infrared Thermography (MIRT) Method—A Numerical Modeling and Experimental Approach

Defect Detection in CFRP Concrete Reinforcement Using the Microwave Infrared Thermography (MIRT) Method—A Numerical Modeling and Experimental Approach

Pulsed Thermography Dataset for Training Deep Learning Models

Inspection of Spot Welded Joints with the Use of the Ultrasonic Surface Wave

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