Thoughts on the importance of similitude and multi-axial loads when assessing the durability and damage tolerance of adhesively-bonded doublers and repairs
File(s)
Published version
Author(s)
Kinloch, Anthony
Jones, Rhys
Chandwani, Ramesh
Timbrell, Chris
Peng, Daren
Type
Journal Article
Abstract
Adhesively bonded doublers and adhesively bonded repairs are extensively used to extend the operational life of metallic aircraft structures. Consequently, this paper focuses on the tools needed to address sustainment issues associated with both adhesively bonded doublers and adhesively bonded repairs to (metallic) aircraft structures, in a fashion that is consistent with the building-block approach mandated in the United States Air Force (USAF) airworthiness certification standard MIL-STD-1530D and also in the United States (US) Joint Services Structural Guidelines JSSG-2006. In this context, it is shown that the effect of biaxial loads on cohesive crack growth in a bonded doubler under both constant amplitude fatigue loads and operational flight loads can be significant. It is also suggested that as a result, for uniaxial tests to replicate the cohesive crack growth seen in adhesively bonded doublers and adhesively bonded repairs under operational flight loads, the magnitude of the applied load spectrum may need to be continuously modified so as to ensure that the crack tip similitude parameter in the laboratory tests reflects that seen in the full-scale aircraft.
Date Issued
2023-11
Date Acceptance
2023-11-04
Citation
Aerospace, 2023, 10 (11)
ISSN
2226-4310
Publisher
MDPI AG
Journal / Book Title
Aerospace
Volume
10
Issue
11
Copyright Statement
© 2023 by the authors. Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (https://creativecommons.org/licenses/by/4.0/).
License URL
Identifier
https://www.mdpi.com/2226-4310/10/11/946
Publication Status
Published
Article Number
946
Date Publish Online
2023-11-07