In this article, we examine the possibility of using active infrared thermography as a nontraditional, nondestructive evaluation method (NDE) for the testing of adhesive joints. Attention was focused on the load-bearing wing structure and related structural joints, specifically the adhesive joints of the wing spar caps and the skins on the wing demonstrator of a small sport aircraft made mainly of a carbon composite. The Pulse Thermography (PT) method, using flash lamps for optical excitation, was tested. The Modified Differential Absolute Contrast (MDAC) method was used to process the measured data to reduce the effect of the heat source's inhomogeneity and surface emissivity. This method demonstrated a very high ability to detect defects in the adhesive joints. The achieved results are easy to interpret and use for both qualitative and quantitative evaluation of the adhesive joints of thin composite parts.

Department of Aerospace Engineering Faculty of Mechanical Engineering Czech Technical University Prague Technická 4 160 00 Praha 6 Czech Republic

Department of Mechanics Biomechanics and Mechatronics Faculty of Mechanical Engineering Czech Technical University Prague Technická 4 160 00 Praha 6 Czech Republic

Zobrazit více v PubMed

Kostroun T., Dvořák M. Non-Destructive Evaluation of Small Aircraft Wing Adhesive Joints using Pulse Infrared Thermography Method; Proceedings of the 58th International Scientific Conference Experimental Stress Analysis; Sobotín, Czech Republic. 19–22 October 2020; Ostrava, Czech Republic: VSB-TUO; 2020. pp. 225–232.

AMC CS-VLA . Acceptable Means of Compliance-Certification Specifications for Very Light Aeroplanes. EASA; Colagne, Germany: 2009. [(accessed on 22 January 2021)]. Available online: www.easa.eu.

Torres M., Piedra S., Ledesma S., Velázquez A.E.C., Angelucci G. Manufacturing Process of High Performance–Low Cost Composite Structures for Light Sport Aircrafts. Aerospace. 2019;6:11. doi: 10.3390/aerospace6020011. DOI

Li R., Lu Z.H. Analysis of Manufacturing Technology of Composite Materials in Light Sport Aircraft. Adv. Mater. Sci. Technol. 2019;1:7–12. doi: 10.37155/2717-526X-0101-2. DOI

Pora J. Composite materials in the airbus A380—From history to future; Proceedings of the ICCM13; Beijing, China. 25–29 June 2001; Beijing, China: Plenary Lecture; 2001.

Dvořák M., Růžička M., Kulíšek V., Běhal J., Kafka V. Damage Detection of the Adhesive Layer of Skin Doubler Specimens Using SHM System Based on Fibre Bragg Gratings; Proceedings of the 5th European Workshop on Structural Health Monitoring; Sorento, Italy. 28 June–4 July 2010; Lancaster, PA, USA: DEStech Publications, Inc.; 2010. pp. 70–75.

Heslehurst R.B. Defects and Damage in Composite Materials and Structures. CRC Press; Boca Raton, FL, USA: 2014. pp. 59–77. DOI

Beine C., Boller C., Netzelmann U., Porsch F., Venkat R., Schulze M., Bulavinov A., Heuer H. NDT for CFRP Aeronautical Components A Comparative Study; Proceedings of the 2nd International Symposium on NDT in Aerospace 2010, DGZfP; Hamburg, Germany. 22–24 November 2010.

Ehrhart B., Valeske B., Muller C.E., Bockenheimer C. Methods for the Quality Assessment of Adhesive Bonded CFRP Structures—A Resumé; Proceedings of the 2nd International Symposium on NDT in Aerospace 2010, DGZfP; Hamburg, Germany. 22–24 November 2010.

Yılmaz B., Jasiūnienė E. Advanced ultrasonic NDT for weak bond detection in composite-adhesive bonded structures. Int. J. Adhes. Adhes. 2020:102. doi: 10.1016/j.ijadhadh.2020.102675. DOI

Workman G.L., Kishoni D., Moore P.O. Nondestructive Testing Handbook, Volume 7–Ultrasonic Testing. 3rd ed. ASNT; Columbus, OH, USA: 2007. pp. 267–299.

Meola C., Boccardi S., Carlomagno G.M. Infrared Thermography in Evaluation of Aerospace Composite Materials. Woodhead Publishing; Cambridge, UK: 2017. pp. 25–56, 98–103.

Ciampa F., Mahmoodi P., Pinto F., Meo M. Recent Advances in Active Infrared Thermography for Non-Destructive Testing of Aerospace Components. Sensors. 2018;18:609. doi: 10.3390/s18020609. PubMed DOI PMC

Qu Z., Jiang P., Zhang W. Development and Application of Infrared Thermography Non-Destructive Testing Techniques. Sensors. 2020;20:3851. doi: 10.3390/s20143851. PubMed DOI PMC

Schroeder J.A., Ahmed T., Chaundry B., Shepard S. Non-destructive testing of structural composites and adhesively bonded composite joints: Pulsed thermography. Compos. Part A. 2002;33:1511–1517. doi: 10.1016/S1359-835X(02)00139-2. DOI

Maldaque X. Theory and Practice of Infrared Technology for Nondestructive Testing. John Wiley & Sons; New York, NY, USA: 2011. pp. 343–366.

Wen B., Zhou Z., Zeng B., Yang C., Fang D., Xu Q., Shao Y., Wan C. Pulse-heating infrared thermography inspection of bonding defects on carbon fiber reinforced polymer composites. Sci. Prog. 2020;103 doi: 10.1177/0036850420950131. PubMed DOI PMC

Deane S., Avdelidis N.P., Castanedo I.C., Zhang H., Nezhad H.Y., Williamson A.A., Mackley T., Davis M.J., Maldague X., Tsourdos A. Application of NDT thermographic imaging of aerospace structures. Infrared Phys. Technol. 2019;97:456–466. doi: 10.1016/j.infrared.2019.02.002. DOI

Vavilov V.P., Burleigh D.D. Review of pulsed thermal NDT: Physical principles, theory and data processing. NDT E Int. 2015;73:28–52. doi: 10.1016/j.ndteint.2015.03.003. DOI

Moustakidis S., Anagnostis A., Karlsson P., Hrissagis K. Non-destructive inspection of aircraft composite materials using triple IR imaging. IFAC-PapersOnLine. 2016;49:291–296. doi: 10.1016/j.ifacol.2016.11.050. DOI

Chen D., Zhang X., Zhang G., Zhang Y., Li X. Infrared Thermography and Its Applications in Aircraft Non-destructive Testing; Proceedings of the 2016 International Conference on Identification, Information and Knowledge in the Internet of Things; Beijing, China. 20–21 October 2016; Beijing, China: IIKI; 2016. pp. 374–379. DOI

Shepard S.M. Proceedings of the IV Conferencia Panamericana de END. AAENDE; Buenos Aires, Argentina: Oct, 2007. Flash Thermography of Aerospace Composites.

Rajic N., Rowlands D., Tsoi K.A. An Australian Perspective on the Application of Infrared Thermography to the Inspection of Military Aircraft; Proceedings of the 2nd International Symposium on NDT in Aerospace 2010, DGZfP; Hamburg, Germany. 22–24 November 2010.

Genest M., Castanedo I.C., Piau J.M., Guibert S., Susa M., Bendada A., Maldague X., Brothers M., Fahr A. Comparison of Thermography Techniques for Inspection of F/A-18 Honeycomb Structures; Proceedings of the Aircraft Aging 2007 Conference; Naples, Italy. 16–18 September 2007.

ASTM E1461-13 . Standard Test Method for Thermal Diffusivity by the Flash Method. ASTM International; West Conshohocken, PA, USA: 2013. [(accessed on 22 January 2021)]. Available online: www.astm.org.

Clark L.M., Taylor R.E. Radiation loss in the flash method for thermal diffusivity. J. Appl. Phys. 1975;46:714–719. doi: 10.1063/1.321635. DOI

Kim S., Kim Y. Improvement of specific heat measurement by the flash method. Thermochim. Acta. 2007;455:30–33. doi: 10.1016/j.tca.2006.11.028. DOI

Benítez H.D., Castando I.C., Bendada A., Maldague X., Loaiza H., Caicedo E. Definition of a new thermal contrast and pulse correction for defect quantification in pulsed thermography. Infrared Phys. Technol. 2008;51:160–167. doi: 10.1016/j.infrared.2007.01.001. DOI

Kostroun T., Pilař J., Dvořák M. Design of active infrared thermography NDT system with optical excitation; Proceedings of the 49th International Conference DEFEKTOSKOPIE 2019/NDE for Safety; České Budějovice, Czech Republic. 5–9 November 2019; Brno, Czech Republic: VUT v Brně; 2019. pp. 75–85.

Ospina F.J.F., Benitez H.D. From local to global analysis of defect detectability in infrared non-destructive testing. Infrared Phys. Technol. 2014;63:211–221. doi: 10.1016/j.infrared.2013.12.017. DOI

Almond P.D., Peng W. Thermal imaging of composites. J. Microsc. 2001;201:163–170. doi: 10.1046/j.1365-2818.2001.00762.x. PubMed DOI

Air Accidents Investigation Institute. [(accessed on 20 December 2020)]; Available online: https://uzpln.cz/pdf/20171113113844.pdf.

German Federal Bureau of Aircraft Accidents Investigation. [(accessed on 20 December 2020)]; Available online: https://www.bfu-web.de/EN/Publications/Investigation%20Report/2003/Report_03_3X164-0-Heppenheim-DuoDiscus.pdf?__blob=publicationFile.

Special Issue: Selected Papers from Experimental Stress Analysis 2020