Aircraft composites assessment by means of transient thermal NDT
TL;DR: In this article, transient thermal non-destructive testing (NDT) is used for assessing aircraft composites, which can be used for both reducing manufacturing costs and out-ofservice time of aircraft due to maintenance.
About: This article is published in Progress in Aerospace Sciences.The article was published on 2004-04-01. It has received 182 citations till now. The article focuses on the topics: Composite repairs & Nondestructive testing.
Citations
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TL;DR: A general introduction to infrared thermography and the common procedures for temperature measurement and non-destructive testing are presented and developments in these fields and recent advances are reviewed.
Abstract: The intensity of the infrared radiation emitted by objects is mainly a function of their temperature. In infrared thermography, this feature is used for multiple purposes: as a health indicator in medical applications, as a sign of malfunction in mechanical and electrical maintenance or as an indicator of heat loss in buildings. This paper presents a review of infrared thermography especially focused on two applications: temperature measurement and non-destructive testing, two of the main fields where infrared thermography-based sensors are used. A general introduction to infrared thermography and the common procedures for temperature measurement and non-destructive testing are presented. Furthermore, developments in these fields and recent advances are reviewed.
658 citations
Cites background or methods from "Aircraft composites assessment by m..."
...Thermal images of defects in drilled holes (frame with permission from [144])....
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...An example is [144], where several different real defects, such as notches, drilled holes, impact damage and through skin assessment, were studied by means of pulsed and pulsed phase IRT, taking into account thermal modeling for the evaluation of integrity....
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TL;DR: In this article, the area of structural bonded repair of composites is broadly reviewed, starting from damage assessment to automation, to identify current scientific challenges and future opportunities, and the authors propose a robust, reliable and repeatable structural bond repair procedures to restore damaged composite components.
388 citations
TL;DR: In this article, the theoretical and experimental aspects of three active thermography approaches: pulsed thermography, lock-in thermography and vibrothermography are discussed in relation to the nondestructive evaluation (NDE) of honeycomb sandwich structures.
Abstract: In this article, the theoretical and experimental aspects of three active thermography approaches: pulsed thermography (PT), lock-in thermography (LT), and vibrothermography (VT), are discussed in relation to the nondestructive evaluation (NDE) of honeycomb sandwich structures. For this purpose, two standard specimens with simulated defects (delaminations, core unbonds, excessive adhesive, and crushed core) were tested, and results were processed, examined, and compared. As will be pointed out, the similarities and differences between these active approaches allow conclusions to be made about the most suitable approach for a particular application. In addition, results from NDE inspection by X-rays and c-scan ultrasounds are provided and discussed for reference.
262 citations
TL;DR: In this paper, the authors experimentally tested three composite structures made of glass fiber-reinforced plastic, hybrid composite with a core made of the same material and face sheets made of aluminum alloy and a carbon fiber reinforced plastic structure extracted from the vertical stabilizer of a military aircraft.
247 citations
Cites methods from "Aircraft composites assessment by m..."
...The authors of [12] presented the results of damage detection and localization (notches, delaminations and drilling defects) in aircraft composite structures using the transient thermography approach....
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TL;DR: In this paper, a comprehensive review of shearography and active thermography and their applications in nondestructive evaluation of materials is presented, and a comparison of the advantages and limitations of two techniques for non-destructive evaluation is also presented.
Abstract: Shearography and thermography are optical techniques, both proven to be valuable tools for material nondestructive evaluation. Papers on these topics, however, are scattered and mainly appeared in optical journals. For the convenience of the materials community, this paper aims to present a comprehensive review of shearography and active thermography and their applications in nondestructive evaluation of materials. Both techniques enjoy the merits of full-field, non-contact and allowing speedy detection of material defects in metal, non-metal as well as composites materials. However, they are fundamentally different in flaw detection mechanisms. Shearography measures materials’ mechanical response to stresses, whereas active thermography measures material's heat-transfer response to an instantaneous thermal excitation. A comparison of the advantages and limitations of two techniques for nondestructive evaluation will also be presented.
219 citations
References
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TL;DR: In this paper, a concept of delamination factor F d (i.e., the ratio of the maximum diameter D max in the damage zone to the hole diameter D ) is proposed to analyze and compare easily the delamination degree in the drilling of carbon fiber-reinforced plastic (CFRP) composite laminates.
Abstract: In this paper, a concept of delamination factor F d (i.e. the ratio of the maximum diameter D max in the damage zone to the hole diameter D ) is proposed to analyze and compare easily the delamination degree in the drilling of carbon fiber-reinforced plastic (CFRP) composite laminates. Experiments were performed to investigate the variations of cutting forces with or without onset of delamination during the drilling operations. The effects of tool geometry and drilling parameters on cutting force variations in CFRP composite materials drilling were also experimentally examined. The experimental results show that the delamination-free drilling processes may be obtained by the proper selections of tool geometry and drilling parameters. The effects of drilling parameters and tool wear on delamination factor are also presented and discussed. Cutting temperature has long been recognized as an important factor influencing the tool wear rate and tool life. An experimental investigation of flank surface temperatures is also presented in this paper. Experimental results indicated that the flank surface temperatures increase with increasing cutting speed but decreasing feed rate. Optimal cutting conditions are proposed to avoid damage from burning during the drilling processes.
634 citations
TL;DR: In this article, the fundamental theory of pulsed phase thermography (PPT) processing method is presented including notes on thermal waves, pulsed thermography and lockin thermography.
278 citations
TL;DR: In this article, transient thermography was employed in the inspection of defects in various aircraft composite panels, including notches on aluminium alloy panels under carbon or boron composite patching, a simulation of delamination on a BORON composite patch, and fibre breakout on carbon composites.
Abstract: Transient thermography was employed in the inspection of defects in various aircraft composite panels. Three different categories of defects were investigated in the laboratory; notches on aluminium alloy panels under carbon or boron composite patching, a simulation of delamination on a boron composite patch, and fibre breakout on carbon composites. In all situations, the defects were artificially created. After detecting the defects, quantitative analysis concerning the contrast of the detected defects was carried out. Finally, information about the size of the artificial delaminated panel in relation to transient time was also performed.
237 citations
TL;DR: In this paper, several experimental investigations of newly developed thermographic NDT techniques based on the transient temperature measurements are described and several experimental results of the pulse heating NDT and the lock-in NDT are shown.
180 citations
TL;DR: In this paper, the use of different thermal non-destructive testing techniques to rapidly inspect carbon fiber composite aircraft components was compared and the results were verified with underwater ultrasonic c-scans.
Abstract: This paper compares the use of different thermal non-destructive testing techniques to rapidly inspect carbon fibre composite aircraft components. Samples were prepared to simulate inclusions and barely visible impact damage in carbon fibre reinforced plastic laminate which represent faults in the manufacturing process and in-service environment respectively. The limits of material fault detection were then compared for transient and lock-in thermography and the results were verified with underwater ultrasonic c-scans. The paper concludes that lock-in thermography is a more powerful technique to detect impact damage and that transient thermography is more suitable for detecting inclusions. Thermal non-destructive testing is up to 30 times quicker than underwater ultrasonic c-scanning and may ultimately provide the solution to the problem of rapid quantitative in-service and manufacturing process inspection of commercial aircraft components.
157 citations