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Analyses of criticality for multiple-site delaminations in the flap spar of Finnish F/A-18 aircraft

Published online by Cambridge University Press:  13 August 2020

J. Jokinen*
Affiliation:
Tampere University, Faculty of Engineering and Natural Sciences, P.O.Box 589, FI-33014, Tampere, Finland
M. Kanerva
Affiliation:
Tampere University, Faculty of Engineering and Natural Sciences, P.O.Box 589, FI-33014, Tampere, Finland
M. Wallin
Affiliation:
Patria Aviation, Lentokonetehtaantie 3, FI-35600, Halli, Finland
O. Saarela
Affiliation:
Aalto University, School of Engineering, Department of Mechanical Engineering, P.O.Box 14300, FI-00076, Aalto, Finland

Abstract

Metal-composite airframes will suffer various defects during their lifetime. One category of defects is composite laminate delamination. This study evaluates the criticality of delaminations existing around adjacent fastener holes in the carbon-fibre-reinforced plastic spar web of the F/A-18 aircraft’s trailing-edge flap. The evaluation is based on experiments and analyses. First, an intensive experimental program for determining necessary material values of F/A-18 is described. Multiple delaminations of the flap spar web are then modelled by varying the set of delaminated hole edges and the interface of delamination. The interaction of defects at the start of delamination propagation is studied via the developed interaction parameter. The results suggest that the interaction parameter can show significant differences in the interaction per delamination case and that the interface of delamination is an important variable. Finally, operator-dependent control parameters are studied, and it is found that the criticality of a delamination case is merely dependent on true material parameters.

Type
Research Article
Copyright
© The Author(s), 2020. Published by Cambridge University Press on behalf of Royal Aeronautical Society

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References

REFERENCES

Mueller, E.M., Starnes, S., Strickland, N., Kenny, P. and Williams, C. The detection, inspection, and failure analysis of composite wing skin defect on a tactical aircraft, Compos. Struct., 2016, 145, pp 186193.CrossRefGoogle Scholar
Viitanen, T., Varis, P. and Siljander, A. A review of aeronautical fatigue investigations in Finland March 2015 to March 2017, 35th Conference of the International Committee of Aeronautical Fatigue and Structural Integrity (ICAF), 5–6 June 2017, Nagoya, Japan, National Review – Finland, ICAF Doc no. 2433Google Scholar
Wisnom, M.R. The role of delamination in failure of fibre-reinforced composites, Philos. Trans. R. Soc. A, 2012, 370, pp 18501870.CrossRefGoogle ScholarPubMed
Bolotin, V.V. Delaminations in composite structures: its origin, buckling, growth and stability, Compos. Part B Eng., 1996, 27, pp 129145.CrossRefGoogle Scholar
Hintikka, P. Determination of interlaminar fracture toughness of composite laminates, master’s thesis, Helsinki University of Technology, 2009 (in Finnish)Google Scholar
Partridge, I.K. and CartiÉ, D.R.D. Delamination resistant laminates by Z-Fiber pinning: Part I manufacture and fracture performance, Compos. Part A Appl. S, 2005, 36, pp 5564.CrossRefGoogle Scholar
de Moura, M.F.S.F., Campilho, R.D.S.G., Amaro, A.M. and Reis, P.N.B. Interlaminar and intralaminar fracture characterization of composites under mode I loading, Compos. Struct., 2010, 92, pp 144149.CrossRefGoogle Scholar
Senthil, K., Arockiarajan, A., Palaninathan, R., Santhosh, B. and Usha, K.M. Defects in composite structures: Its effects and prediction methods – A comprehensive review, Compos. Struct., 2013, 106, pp 139149.CrossRefGoogle Scholar
Brouzoulis, J. and FagerstrÖm, M. An enriched shell element formulation for efficient modeling of multiple delamination propagation in laminates, Compos. Struct., 2015, 126, pp 196206.CrossRefGoogle Scholar
Liu, P.F. and Zheng, J.Y. On the through-the-width multiple delamination, and buckling and postbuckling behaviors of symmetric and unsymmetric composite laminates, Appl. Compos. Mater., 2013, 20, pp 11471160.CrossRefGoogle Scholar
Chen, J. and Fox, D. Numerical investigation into multi-delamination failure of composite T-piece specimens under mixed mode loading using a modified cohesive model, Compos. Struct., 2012, 94, pp 20102016.CrossRefGoogle Scholar
Ryu, C.-H., Park, S.-H., Kim, D.-H., Jhang, K.-Y. and Kim, H.-S. Nondestructive evaluation of hidden multi-delamination in a glass-fiber-reinforced plastic composite using terahertz spectroscopy, Compos. Struct., 2016, 156, pp 338347.CrossRefGoogle Scholar
Riccio, A., Giordano, M. and Zarrelli, M. A linear numerical approach to simulate the delamination growth initiation in stiffened composite panels, J. Compos. Mater., 2010, 44, pp 18411866.CrossRefGoogle Scholar
Shen, F., Lee, K.H. and Tay, T.E. Modeling delamination growth in laminated composites, Compos. Sci. Technol., 2001, 61, pp 12391251.CrossRefGoogle Scholar
Jokinen, J. Numerical modeling of delamination, master’s thesis, Helsinki University of Technology, 2009 (in Finnish)Google Scholar
ISO 15024:2001, Fibre-reinforced plastic composites — Determination of mode I interlaminar fracture toughness, GIC, for unidirectionally reinforced materials, 2001.Google Scholar
ASTM D7905/D7905M-14, Standard Test Method for Determination of the Mode II Interlaminar Fracture Toughness of Unidirectional Fiber-Reinforced Polymer Matrix Composites, ASTM International, 2014, West Conshohocken, PA.Google Scholar
ASTM D6671/D6671M – 13e1, Standard Test Method for Mixed Mode I–Mode II Interlaminar Fracture Toughness of Unidirectional Fiber Reinforced Polymer Matrix Composites, ASTM International, 2013, West Conshohocken, PA.Google Scholar
Benzeggagh, M.L. and Kenane, M. Measurement of mixed-mode delamination fracture toughness of unidirectional glass/epoxy composites with mixed-mode bending apparatus, Compos. Sci. Technol., 1996, 56, pp 439449.CrossRefGoogle Scholar
Reeder, J.R. An evaluation of mixed-mode delamination failure criteria, NASA Technical Memorandum 104210, 1992.Google Scholar
Hintikka, P., Wallin, M. and Saarela, O. The effect of moisture on the interlaminar fracture toughness of CFRP laminate, 27th International Congress of the Aeronautical Sciences, 2010.Google Scholar
Jokinen, J., Wallin, M. and Saarela, O. Delamination analysis of a trailing edge flap, International Committee on Aeronautical Fatigue and Structural Integrity, Helsinki, 2015.Google Scholar
Shokrieh, M.M., Rajabpour-Shirazi, H., Heidari-Rarani, M. and Haghpanahi, M. Simulation of mode I delamination propagation in multidirectional composites with R-curve effects using VCCT method, Comp. Mater. Sci., 2012, 65, pp 6673.CrossRefGoogle Scholar
Wang, J.T. and Raju, I.S. Strain energy release rate formulae for skin-stiffener debond modeled with plate elements, Eng. Fract. Mech., 1996, 54, pp 211228.CrossRefGoogle Scholar
Krueger, R. The Virtual Crack Closure Technique: History, Approach and Applications, NASA/ CR-2002-211628, 2002.Google Scholar
Jokinen, J. and Kanerva, M. Analysis of cracked lap shear testing of tungsten-CFRP hybrid laminates, Eng. Fract. Mech., 2017, 175, pp 184200.CrossRefGoogle Scholar
Burianek, D.A., Giannakopoulos, A.E. and Spearing, S.M. Modeling of facesheet crack growth in titanium–graphite hybrid laminates, Part I, Eng. Fract. Mech., 2003, 70, pp 775798.CrossRefGoogle Scholar
de Morais, A.B., de Moura, M.F., GonÇalves, J.P.M. and Camanho, P.P. Analysis of crack propagation in double cantilever beam tests of multidirectional laminates, Mech. Mater., 2003, 35, pp 641652.CrossRefGoogle Scholar
Lindgren, M., Bergman, G., Kakkonen, M., Lehtonen, M., Jokinen, J., Wallin, M., Saarela, O. and Vuorinen, J. Failure analysis of a leaching reactor made of glass-fiber reinforced plastic, Eng. Fail. Anal., 2016, 60, pp 117136.CrossRefGoogle Scholar
Jokinen, J., Wallin, M. and Saarela, O. Applicability of VCCT in mode I loading of yielding adhesively bonded joints-a case study, Int. J. Adhes. Adhes., 2015, 62, pp 8591.CrossRefGoogle Scholar
Aakkula, J., Jokinen, J. and Saarela, O. Testing and modelling of DIARC plasma coated elastic-plastic steel wedge specimens, Int. J. Adhes. Adhes., 2016, 68, pp 219228.CrossRefGoogle Scholar
Finnish Air Force, http://ilmavoimat.fi/kalustokuvastot Accessed 8.3.2018.Google Scholar
Hakuri, O. Mixed-mode failure criterions for delamination analysis, bachelor’s thesis, Aalto University, 2015 (in Finnish), http://urn.fi/URN:NBN:fi:aalto-201511265356 Google Scholar
Jokinen, J., Kanerva, M. and Saarela, O. Multi-site delamination analysis using virtual crack closure technique a composite aircraft wing flap, 31st Congress of the International Council of the Aeronautical Sciences (ICAS), Belo Horizonte, Brazil, 2018.Google Scholar
Azuma, K. and Li, Y. Interaction factors for two elliptical embedded cracks with a wide range of aspect ratios, AIMS Mater. Sci., 2017, 4, pp 328339.CrossRefGoogle Scholar
Yan, X. and Miao, C. Interaction of multiple cracks in a rectangular plate, Appl. Math. Model., 2012, 36, pp 57275740.CrossRefGoogle Scholar
Galatolo, R. and Nilsson, K.-F. An experimental and numerical analysis of residual strength of butt-joints panels with multiple site damage, Eng. Fract. Mech., 2001, 68, pp 14371461.CrossRefGoogle Scholar
Park, J.H., Singh, R., Pyo, C.R. and Atluri, S.N. Integrity of aircraft structural elements with multi-site fatigue damage, Eng. Fract. Mech., 1995, 51, pp 361380.CrossRefGoogle Scholar
Wang, W., Rans, C., Alderliesten, R.C. and Benedictus, R. Predicting the influence of discretely notched layers on fatigue crack growth in fibre metal laminates, Eng. Fract. Mech., 2015, 145, pp 114.CrossRefGoogle Scholar