Bonding of CFRP primary aerospace structures - discussion of the certification boundary conditions and related technology fields addressing the needs for development

• Published in: Composite interfaces Vol. 22; no. 8; pp. 795 - 808
• Main Authors: Schmid Fuertes, Theodor A., Kruse, Thomas, Körwien, Thomas, Geistbeck, Matthias
• Format: Journal Article
• Language: English
• Published: Taylor & Francis 13.10.2015
• Subjects: adhesive; aerospace; bonding; certification; composite
• ISSN: 0927-6440; 1568-5543
• DOI: 10.1080/09276440.2015.1077048

Today, the application of bonding technology for primary aerospace structures is limited due to the certification regulations. State of the art is an additional application of fasteners which is limiting the benefits of the application of composite bonded joints. This article provides an overview of the current state of the art of certification compliance within the context of bonded CFRP primary aerospace structures. Beginning with the boundary conditions and the background of the certification regulations, the current framework for the development of composite bonded joints is described including the experiences within the aerospace industry as well as the physical principles that are leading to initial damages and uncertainties within a composite bonded joint. Also, the role and interaction of different technology streams such as surface preparation, process safety, material and adhesive development, and design and sizing concepts to enable a secured roadmap to certification is discussed. The resulting needs for current and future technology development and their interaction within the different disciplines is described. Also, solution approaches to build a roadmap to certification of CFRP-bonded joints are highlighted.