Modelling Fatigue Crack Growth Rates in Aluminium Plates Reinforced by Bonded Fibre-Metal Laminates for Fatigue Life Extension

Abstract:

Aircraft structural design and manufacture is moving towards lighter structures that have extended lives and improved damage tolerance. Hybrid structures are a possible solution to improve damage tolerance. They are a combination of metallic structure locally reinforced with adhesively bonded damage tolerant straps. In the present study a 3D finite element model has been developed with a bond line delamination growing under a fatigue law. A series of fatigue delamination tests on bonded aluminium were performed to provide input data. An iterative model for crack and debonding growth was developed to describe how debonding influence crack stress intensity and crack profile, which in turn influence debonding. The model predicts decrease in stress intensity on the bonded face and an overall retardation of fatigue crack growth rates. The stress intensity factor was predicted to vary through the thickness of the substrate due to the phenomenon of secondary bending and also the bridging effect caused by the presence of the reinforcing strap.

• Periodical: Advanced Materials Research (Volumes 891-892)
• Pages: 1803-1809
• DOI: https://doi.org/10.4028/www.scientific.net/AMR.891-892.1803
• Online since: March 2014
• Authors: Jeremy Doucet, Xiang Zhang, Philip E. Irving
• Keywords: Bonded Crack Retarder, Bonded Strap, Finite Element Analysis (FEA), Integral Metallic Structure, Life Enhancement

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