Delamination Tolerance in Composites under Fatigue Loading

K Lok Singh, B Dattaguru

Abstract


Delamination is one of the most commonly occurring defects in laminated composite structures. Under operating fatigue loads on the laminate this delamination could grow and totally delaminate certain number of layers from the base laminate. This will result in loss of both compressive residual strength and buckling margins available. In this paper, geometrically non-linear analysis and evaluation of Strain Energy Release Rates using MVCCI technique is presented. The problems of multiple delamination, effect of temperature exposure and delamination from pin loaded holes are addressed. Numerical results are presented to draw certain inferences of importance to design of high technology composite structures such as aircraft wing.

Keywords


Composite; Delamination; Fatigue

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References


J.D. Whitcomb, Mechanics of instability related delamination growth, NASA-TM-100622, NASA Langley Research Center, Hampton, VA, USA 1988.

J.D. Whitcomb, Three dimensional analysis of a post-buckled embedded delamination, NASA-TP-2823, NASA Langley Research Center, Hampton VA, USA 1988.

T.H. Megson, Aircraft structures for engineering students, Elsevier Butterworth Heinemann, London 3rd edition, 1999.

Nikolaos Kontis, Damage Tolerance of Composite Stiffened Structures, Ph. D. Thesis, University of Bath, Department of Mechanical Engineering, May 2008.

D.J. Wilkins, J.R. Eisenmann, R.A. Camin Margolis and W.S. Benson, Characterizing delamination growth in graphite epoxy, Damage in composite materials, ASTM STP 775, Reifisnider KL, Ed., American Society for Testing & Materials, 1982, 168–183.

C.G. Gustafson & M.Hojo, “Delamination fatigue crack growth in unidirectional Graphite/ Epoxy laminates”, Journal of Reinforced Plastics & Composites, 6, 1987, 36–52.

M. Hojo, K. Tanaka, C. Gustafson & R. Hayashi, Proc. Sixth Int. conf. on Composite Materials. & Second European conf. on comp. materials, 4, 1987, 4.222–4.231.

O.C. Zienckiwicz and R.L. Taylor, “The finite element method”, 4th edition McGraw Hill International editions, 1991.

K.L. Singh, B. Dattaguru and T.S. Ramamurthy, “Fracture analysis of delaminated composite panels in compression using numerically integrated MVCCI”, Mechanics of Advanced Materials and Structures, 13(4), 2006, 303–316.

E.F. Rybicki and M. F. Kanninen, “A finite element calculation of stress intensity factors by a modified crack closure integral”, Engineering Fracture Mechanics, 9, 1977, 931–938.

F.G. Buchholz, “Improved formulae for FE calculation of the strain energy release rate by the Modified Crack Closure Integral method”, Proc. 4th World Congress and Exhibition in FEM, Interlaken, 1984, 650–659.

T.S. Ramamurthy, T. Krishnamurthy, K. Badari Narayana, B. Dattaguru and K. Vijayakumar, “Modified crack closure integral method with quarter-point elements”, Mechanics. Research Communications, 13(4), 1986, 179–186.

I.S. Raju, “Calculation of strain energy release rates with higher order and singular elements” Engineering Fracture Mechanics, 28, 1987, 251–274.

G.S. Palani, N.R. Iyer and B. Dattaguru, “Fracture analysis of cracked plate panels using NI-MVCCI technique” Transactions of the Indian Institute of Metals, 58 (2–3), 2005, 437–444.

J. Hiroshi Suemasu, “Post-buckling behavior of composite panels with multiple de-laminations”, Journal of Composite. Materials, 27(11), 1993, 1077–1096.

Shun-Fa Hwang & Guu-Huann Liu, “Buckling behavior of composite laminates with multiple de-laminations under uniaxial compression”, Composite Structures, 53, 2001, 235–243.

T.A. Collings and D.E.W. Stone, “Hygro-thermal effects in CFRP laminates: strains induced by temperature and moisture”, Composites, 16(4), 1985, 307–310.

K. Satish Kumar, “Elasto-plastic contact stress analysis of lug joints under cyclic loading”, Ph.D. Thesis, Aerospace Engineering Department, Indian Institute of Science, 1996.


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