Engineering Transactions, 55, 1, pp. 61–77, 2007
10.24423/engtrans.231.2007

Numerical Modeling of Delamination in GFRP Composites

M. R. KHOSHRAVAN
Faculty of Engineering Mechanical Engineering Department University of Tabriz
Iran, Islamic Republic of

A. YOURDKHANI
Faculty of Engineering Mechanical Engineering Department University of Tabriz
Iran, Islamic Republic of

Polymer matrix composites have become highly relevant structural materials. However, high performance laminates are quite susceptible to transverse cracking and delamination. Transverse cracks may cause significant stiffness losses, accelerate environmentally induced degradation and generate delamination. The characterization and modeling of fracture behavior is thus highly relevant for the design of composite parts. In this paper, the delamination phenomena in the Mixed Mode I+II which is one of the important cause of failure in multilayer composites, are studied. The composite is a GFRP (Glass Fiber Reinforced Plastic) and are studied under static monotonic loading. Using the Irwin–Kies criteria, usual laws of elasticity and VCCT (Virtual Crack Closure Technique), based on finite element method, the SERR (Strain Energy Release Rate) in Mode I, Mode II, and four ratio Modes (GI/GII) are evaluated. The finite element analysis of test bars is carried out using ANSYS5.5 software in two dimensions, and the appropriate boundary conditions are chosen. Our numerical results are compared with known experimental ones and with application of the local effects, such as three-dimensional (3D) effect in the width of the test bar with the shape of MMB (Mixed Mode Bending) specimen, scattering between experimental and numerical results is evaluated and discussed. For the 3D effect, the variation of the stress components in the mid-plane of specimen in which delamination occurs, versus the width of specimen, is obtained. Then the variation of strain energy release rate in different ratio Modes, in the width of test bars is calculated.
Full Text: PDF
Copyright © Polish Academy of Sciences & Institute of Fundamental Technological Research (IPPT PAN).

References

R.M. Jones, Mechanics of composite materials, 2-nd edition, Taylor and Francis, Inc. USA, 1999.

N.E. Janson, R. Larson, Rotational interface formulation for delamination analysis of composite laminates, Computers and Structures, 81, 2705–2716, 2003.

R. Krueger, M. Cvitkovich, K. O’Brien, P. Minguet, Testing and analysis of composite skin/stringer, J. Composite Materials, 34, 15, 1263–1300, 2000.

M.R. Khoshravan, A.R. Jami, Interlaminar stresses in CFRP composites, Proceeding of the International Conference on Advanced Fibers and Polymer Materials, Oct. 19–21, Shanghai, China, 1, 338–342, 2005.

R. Hertzberg, Deformation and fracture mechanics of engineering materials, Section 8.2, Wiley publishing company, 1989.

M.R. Khoshravan, M. Monir Vaghefi, Numerical evaluation of delamination on Mode II in glass fiber reinforced composites, Engineering Transactions, 53, 55–68, 2005.

F. Ducept, P. Davies, D. Gamby, An experimental study to validate tests used to determine mixed mode failure criteria of glass/epoxy composite, Composite Part A 28A, 719–729, 1997.

Z. Zou, S.R. Reid, S. Li, A continuum damage model for delaminations in laminated composites, J. Mechanics and Physics of Solids, 51, 333–356, 2003.

J.H. Crews, J.R. Reeder, A mixed mode bending apparatus for delamination testing, NASA Technical Memorandum 100662, 1988.

J.R. Reeder and J.H. Crews, Nonlinear analysis and redesign of the mixed mode bending delamination test, NASA Technical Memorandum 102777, 1991.

F. Ducept, P. Davies, D. Gamby, Mixed mode failure criteria for a glass/epoxy composite and an adhesively bonded composite/composite joint, International Journal of Adhesion and Adhesives, 20, 233–244, 2000.

G.R. Irwin, Fracture Handbook of Physic, VI, Springer, 551–590, 1958.

M.F. Kanninen, An argumented double cantilever beam model for studying crack propagation and arrest, International Journal of Fracture, 9, 1, 83–92,1973.

S. Hashemi, A.J. Kinloch, J.G. Williams, The analysis of interlaminar fracture in uniaxial fiber-polymer composites, Proceedings of the Royal Society of London, A427,173– 199,1990.

R. Krueger, T.K. O’Brien, A shell/3D modeling technique for the analysis of delaminated composite laminates, J. of Composites, Part A: Applied Science and Manufacturing, 32, 1, 25–44,2001.

P. Davies, Analysis of GIC interlaminar fracture test, Applied Composite Materials, Round robin, 1996.

ASTM standard E399-81, Standard test method for plane strain fracture toughness of metallic materials.




DOI: 10.24423/engtrans.231.2007