Hostname: page-component-78c5997874-ndw9j Total loading time: 0 Render date: 2024-11-20T00:09:26.171Z Has data issue: false hasContentIssue false

Using the lead crack framework to reduce durability test duration

Published online by Cambridge University Press:  24 September 2019

L. Molent*
Affiliation:
Aerospace Division, Fishermans Bend, Australia
R. Singh
Affiliation:
Defence Aviation Safety Authority, Melbourne, Australia

Abstract

Aircraft full-scale fatigue tests are expensive and time-consuming to conduct but are a critical item on the certification path of any aircraft design or modification. This paper outlines a proposal that trades cycling hours for increased detail in the teardown of a metallic test article. A method for determining the equivalent demonstrated crack size (and crack growth curve) at the mandated test life utilising the lead crack framework is demonstrated. It is considered that the test duration can be significantly reduced, whilst still achieving all the desired outcomes of a certification program.

Type
Research Article
Copyright
© Crown Copyright. Published by Cambridge University Press 2019

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

Footnotes

A version of this paper was first presented at the 18th Australian International Aerospace Congress in February 2019.

References

REFERENCES

Qualification by analysis. NATO-RTO Report RTO-TR-AVT-092 AC/323(AVT-092) TP/229, 2009.CrossRefGoogle Scholar
Gerlter, J. F-35 Joint Strike Fighter (JSF) Program: background and issues for Congress, Congressional Research Service Report, 26 April 2011.Google Scholar
DEF STAN 00-970 Design and Airworthiness for Service Aircraft, Issue 1. United Kingdom. British Ministry of Defence, 1983.Google Scholar
Aircraft Structural Integrity Program (ASIP), MIL-STD-1530D, US DoD, 2016.Google Scholar
Damage Tolerance and Fatigue Evaluation of Structure, AC 25.571, US Department of Transportation, FAA, USA, 2011.Google Scholar
Molent, L., Barter, S.A. and Wanhill, R.J.H.The lead crack fatigue lifing framework, Fatigue, 2011, 33, pp 323331.CrossRefGoogle Scholar
Molent, L.A review of equivalent pre-crack sizes in aluminium alloy 7050-T7451, Fatigue & Fracture of Engineering Materials & Structures, 2014, 37, pp 10551074.CrossRefGoogle Scholar
Hu, W., Krieg, B., Jackson, P., Mccoy, M., Maxfield, K. and Ogden, R. Challenges and progress in modelling fatigue crack growth under transport aircraft and helicopter type spectra, Proc. 28th ICAF Symposium – Helsinki, 3–5 June 2015.Google Scholar
Molent, L., Barter, S.A., Gordon, M. and Weibler, L.Pseudo fatigue testing for rapid certification to service, Advanced Materials Research, 2014, 891–892, pp 10591064.CrossRefGoogle Scholar
Wanhill, R.J.H. Durability analysis using short and long fatigue crack growth data, Proc. Int Conf Aircraft Damage Assessment and Repair, Melbourne, Aug 1991, pp 100104.Google Scholar
Molent, L., Sun, Q. and Green, A.J. The F/A-18 fatigue crack growth data compendium, DSTO-TR-1677, 2005.Google Scholar
Molent, L. and Sun, Q. Analysis of F/A-18 Hornet crack growth compendium data, DSTO-RR-0378, 2012.Google Scholar
Molent, L., Sun, Q. and Green, A.Characterisation of equivalent initial flaw sizes in 7050 aluminium alloy, Fatigue & Fracture of Engineering Materials & Structures, 2006 29, pp 916937.CrossRefGoogle Scholar
Molent, L. and Sun, Q. Distribution of equivalent pre-crack Size in 7050 aluminium alloy, DSTO-TR-1700, 2006.Google Scholar
Gallagher, J.P. and Molent, L.The equivalence of EPS and EIFS based on the same crack growth life data, J Fatigue, 2015, 80, pp 162170.CrossRefGoogle Scholar
Barter, S., Molent, L., Goldsmith, N. and Jones, R.An experimental evaluation of fatigue crack growth, Engineering Failure Analysis, 2005, 12, (1), pp 99128.CrossRefGoogle Scholar
Molent, L. and Barter, S.A.A comparison of crack growth behaviour in several full-scale airframe fatigue tests, J Fatigue, 2007, 9, pp 10901099.CrossRefGoogle Scholar
Jones, R., Molent, L. and Pitt, S.Understanding crack growth in fuselage lap joints, Theoretical and Applied Fracture Mechanics, 2008, 49, pp 3850.CrossRefGoogle Scholar
Jones, R.Fatigue crack growth and damage tolerance, Fatigue & Fracture of Engineering Materials & Structures, 2014, 37 (5), pp 463483.CrossRefGoogle Scholar
Jones, R., Molent, L. and Walker, K.Fatigue crack growth in a diverse range of materials, J Fatigue, 2012, 40, pp 4350.CrossRefGoogle Scholar
Wanhill, R.J.H. Characteristic stress intensity factor correlations of fatigue crack growth in high strength alloys: reviews and completion of NLR investigations 1985–1990, NLR-TP-2009-256, 2009.Google Scholar
Simpson, D.L., Landry, N., Roussel, J., Molent, L., Graham, A.D. and Schmidt, N. The Canadian and Australian F/A-18 International Follow-On Structural Test Project, Proc. ICAS 2002 Congress, September 2002.Google Scholar
Torregosa, R.F., Hu, W., Ogden, R. and Maxfield, K. Risk-based methods for use in C-130J wing fatigue test interpretation, DST-Group-RR-0449, Australia, 2018.Google Scholar
Molent, L., Dixon, B., Barter, S.A. and Swanton, G.Outcomes from the fatigue testing of seventeen centre fuselage structures, J Fatigue, 2018, 111C, pp 220232.CrossRefGoogle Scholar
Eijkhout, M.T. Fractographic analysis of longitudinal fuselage lapjoint at stringer 42 of Fokker 100 full scale test article TA15 after 126250 simulated flights, Fokker Report RT2160, Fokker Aircraft Ltd., Amsterdam, November 1994.Google Scholar