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An analysis approach toward FAA certification for damage tolerance of aircraft components

Published online by Cambridge University Press:  27 January 2016

F. Abdi*
Affiliation:
Alpha Star Corporation, Long Beach, California, USA
Y. Xue
Affiliation:
Alpha Star Corporation, Long Beach, California, USA
M. Garg
Affiliation:
Alpha Star Corporation, Long Beach, California, USA
B. Farahmand
Affiliation:
Alpha Star Corporation, Long Beach, California, USA
J. Housner
Affiliation:
Alpha Star Corporation, Long Beach, California, USA
K. Nikbin
Affiliation:
Imperial College, London, UK

Abstract

This paper presents a novel analysis approach by considering multiple crack interaction in achieving FAA certification for durability and damage tolerance of exterior attachment installations on an aircraft fuselage according to FAA policy on Certification by Analysis-Supported-by-Test (CAST). Durability and damage tolerance evaluation of an aircraft component requires assessment of damage initiation and fatigue crack propagations under service loading, which consists of complex loading types, paths and variable amplitudes. Both simulation and service experience showed that multiple cracks developed in the fuselage skin and doublers that are made of wrought aluminum alloys. Progressive failure analysis (PFA) tool was used to simulate the fatigue damage initiation life using a scale-down stress-life property. A virtual crack closure technique (VCCT) was implemented to evaluate fatigue crack growth with interactions between cracks from different parts in a component, which preserves conservativeness. The fatigue crack growth data is obtained uniquely from an analytical extension of fatigue crack growth data of thin aluminum sheet. Fatigue crack growth analysis showed that only a few initiated cracks propagated steadily before a crack became visible under inspection, which was validated by comparison to service history. Eventually one crack became dominate in the fracturing process thereby setting an inspection time. Analysis also showed that fatigue damage state in the components at the designed operational life will not exceed the static safety requirements. Therefore, FAA accepted the damage tolerance analysis and the aircraft retained certification with no need for repair.

Type
Research Article
Copyright
Copyright © Royal Aeronautical Society 2014 

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References

1. Federal Aviation Administration, 2011 Engineering Designee Recurrent Seminar, 21 September 2011, Costa Mesa, CA, USA.Google Scholar
2. NASGRO Fracture Mechanics and Fatigue Crack Growth Analysis Software, Version 4.02 September 2002, NASA-JSC and SwRI,.Google Scholar
3. Newman, J.C. A crack opening stress equation for fatigue crack growth, Int J of Fracture, March 1984, 24, (3), pp R131R135.Google Scholar
6. Maligno, A.R., Soutis, C. and Silberschmidt, V.V. An advanced numerical tool to study fatigue crack propagation in aluminum plates repaired with a composite patch, Eng Fracture Mechanics, 2013, 99, pp 6278.Google Scholar
7. Maligno, A.R., Whalley, D.C. and Silberschmidt, V.V. Thermal fatigue life estimation and delamination mechanics studies of multilayered MEMS structures, Microelectronics Reliability, 2012, 52, (8), pp 16651678.Google Scholar
8. Maligno, A.R., Rajaratnam, S., Leen, S. and Williams, E. A three-dimensional (3D) numerical study on fatigue crack growth using remeshing techniques, Eng Fracture Mechanics, 2010, 77, (1), pp 94111.Google Scholar
9. Xie, D., Waas, A.M., Shahwan, K.W., Schroeder, J.A. and Boeman, R.G. Computation of energy release rates for kinking cracks based on virtual crack closure technique, CMES, 2004, 6, (6), pp 515524.Google Scholar
10. Deobald, L., Mabson, G. and Dopker, B., Hoyt, D.M., Baylor, F. and Graesser, D. Interlaminar fatigue element for crack growth based on virtual crack closure technique, 2007, 48th AIAA Structures Structural Dynamics and Materials Conference, 23-26 April 2007, Honolulu, HI, USA.Google Scholar
11. Xie, D, Garg, M., Huang, D. and Abdi, F. Cohesive zone model for surface cracks using finite element analysis, April 2008, AIAA-2008-106742, Chicago, IL, USA.Google Scholar
12. Garg, M., Abumeri, G.H. and Huang, D. Validation of class of applications using progressive failure and discrete cohesive zone model for line and surface cracks, 2009, 50th AIAA/ASME/ASCE/AHS/ASC Structures Structural Dynamics and Materials Conference, 4-7 May 2009, Palm Spring, CA, USA.Google Scholar
13. Garg, M., Abdi, F., Abumeri, G.H. and Heinimann, M. Fatigue life prediction of center cracked Al stiffened panel subject to spectrum loading, 2011, AIAA-SDM Conference, 5-9 April 2011, Denver, CO, USA.Google Scholar
14. Metallic materials properties development and standardization (MMPDS-01), 2001, US Department of Transportation.Google Scholar
15. Forman, R.G., Shivakumar, V., Cardinal, J.W., Williams, L.C. and McKeighan, P.C. Fatigue crack growth database for damage tolerance analysis, August 2005, DOT/FAA/AR-05/15, Final Report.Google Scholar
16. Pettinà, M. Virtual Testing for Fracture Toughness, Fatigue Crack Growth and Fatigue Life Data Estimation of Metallic Components, MSc thesis, April 2012, Università Degli Studi di Padova, Italy.Google Scholar
17. Morris, G. Defining a Standard Formula and Test-method for Fastener Flexibility in Lap-joints, TU Delft thesis, 2004.Google Scholar
18. Stress Analysis of Fatigue Cracks in Mechanically Fastened Joints: An Analytical and Experimental Investigation, TU Delft thesis.Google Scholar
19. Phillips, E.P. An experimental study of fatigue crack growth in aluminum sheet subjected to combined bending and membrane stresses, October 1997, NASA Technical Memorandum 4784.Google Scholar
20. Farahmand, B. and Glassco, J. Fatigue and Fracture Mechanics of High Risk Parts: Application of LEFM & FMDM Theory, 1997, p 186, Chapman and Hall, New York, NY, USA.Google Scholar
21. Farahmand, B. and Abdi, F. Probabilistic fracture toughness, fatigue crack growth estimation resulting from material uncertainties, 2002,, Paper 11569, ASTM Conference, 6-7 November 2002, Miami Beach, FL, USA.Google Scholar
22. Leemans, S., Rohl, P., Huang, D., Abdi, F., Surdenas, J. and Keshavanarayana, R. Certification by analysis: general aviation honeycomb fuselage panels, 2009, SAMPE 2009 Conference, 18-21 May 2009, Baltimore, MD, USA.Google Scholar