Experimental and Modeling Study of the Effect of Corrosion Pitting on Fatigue Failure Locations in Aircraft Components

Bruce R. Crawford; Chris Loader; Qian Chu Liu; Timothy J. Harrison; P. Khan Sharp; Gunnar Härkegård

doi:10.4028/www.scientific.net/AMR.891-892.236

Paper Titles

Effects of Waveform and Cycle Period on Corrosion-Fatigue Crack Growth in Cathodically Protected High-Strength Steels
p.211

Influence of Load Signal Form and Variable Amplitude Loading on the Corrosion Fatigue Behaviour of Aluminium Alloys
p.217

The Effect of Ralstonia pickettii on Environmental Fatigue Crack Growth of 7xxx Series Aluminum Alloys
p.224

The Effect of Corrosion Inhibitors on Environmental Fatigue Crack Growth in Al-Zn-Mg-Cu
p.230

Experimental and Modeling Study of the Effect of Corrosion Pitting on Fatigue Failure Locations in Aircraft Components
p.236

A Model for Predicting the Stress Concentration of Intergranular Corrosion around a Fastener Hole
p.242

Corrosion-Fatigue Crack Growth in Age-Hardened Al Alloys: Examples of Failures and Explanations for Fractographic Observations
p.248

An Extended Finite Element Model Coupled with Level Set Method for Stable Pitting Corrosion
p.254

Managing Fatigue from Corrosion Pits in Aircraft Structures
p.261

HomeAdvanced Materials ResearchAdvanced Materials Research Vols. 891-892Experimental and Modeling Study of the Effect of...

Experimental and Modeling Study of the Effect of Corrosion Pitting on Fatigue Failure Locations in Aircraft Components

Abstract:

It is well established that corrosion pits reduce the fatigue life and structural integrity of aluminum alloy aircraft components. A great deal of research has been conducted in this area in the last 20 years. This problem is not unique to aluminum alloys or aircraft however. Similar problems have been observed in the steel components of other engineered structures such as steel pipelines and steam turbine blades. However the effect of pitting corrosion on the probable location of fatigue failures has been overlooked. This is problematic as corrosion pits have caused fatigue failures in locations and components where they were unexpected, such as the trailing edge flap lug of the F/A 18 fighter aircraft. DSTO have called this problem ‘Corrosion Criticality’. This paper reports the development of Monte-Carlo models of how pitting corrosion affects the location of fatigue failures in two fatigue specimen geometries that have different stress concentration factors (kt). These specimens are a low-kt fatigue life specimen and a high-kt fatigue life specimen with three holes arranged along its centerline. The modeling results for the low-kt specimen are then compared with experimental results for that specimen. The low-kt model produces good estimates of fatigue life and of the probability of fatigue failure at any given location in the specimen’s gauge section. The process that will be followed to develop the high-kt model is outlined. The paper includes a discussion of using the Corrosion Criticality models to reduce the cost of corrosion maintenance by (i) identifying areas in which corrosion inspections are critical and (ii) identify aircraft components for which pitting corrosion will not be a threat to airworthiness during the life of an aircraft.

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Periodical:

Advanced Materials Research (Volumes 891-892)

Pages:

236-241

DOI:

https://doi.org/10.4028/www.scientific.net/AMR.891-892.236

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Online since:

March 2014

Authors:

Bruce R. Crawford*, Chris Loader, Qian Chu Liu, Timothy J. Harrison, P. Khan Sharp, Gunnar Härkegård

Keywords:

Aircraft, Corrosion, Corrosion Fatigue, Probabilistic Modeling, Structural Integrity

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* - Corresponding Author

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