Improving the reliability of a visual inspection of damaged aircraft structural components made of composite materials

• Published in: Nauchnyĭ vestnik MGTU GA (Online) Vol. 25; no. 4; pp. 44 - 55
• Main Author: Davydov, I. A.
• Format: Journal Article
• Language: English; Russian
• Published: Moscow State Technical University of Civil Aviation 06.09.2022
• Subjects: авиация; визуальный контроль; композиционные материалы; техническое обслуживание; эксплуатация воздушного транспорта
• ISSN: 2079-0619; 2542-0119
• DOI: 10.26467/2079-0619-2022-25-4-44-55

   The given article represents the study of the influence of color, surface finish and shape of dents on the reliability of 3D surface dents visual inspection, which are formed due to damage to epoxy composite materials reinforced with carbon fiber resulted from impacts. This article provides an analysis of the influence of surface color of aircraft structural components made of composite materials on the reliability of a visual inspection. The test results are given. Using these values, it is possible to determine the cross-section profiles of surface defects caused by impacts with energy within the range from 5 J to 80 J. The new designs of aircraft, which have been put into service thus far, feature 50 % and more composite materials of the airframe mass and use monolithic carbon fiber composite panels for the fuselage skin. Carbon fiber composite is particularly sensitive to the post-impact compressive strength reduction, and the operating aircraft environment is characterized by an array of sources of impact damages. Samples of the surface appearance of real composite structures of the aircraft on impact is the confidential information. Currently available literature concerning impact damage to composite materials, focuses on impact testing using hemispherical impact elements of typical diameters Ø 15mm, Ø 20 mm or Ø 25 mm. Testing information regarding larger diameter samples is not provided. There is no published research into impact damages to monolithic, fully finished carbon fiber composites.