This paper presents an analytical and experimental study to examine the behaviour of notched carbon/epoxy laminates containing out of plane fibre waviness defects. The open hole tension specimen geometry is modified to include carefully controlled waviness defects. The specimen is proposed to study the interaction between the notch and out of plane waviness. A new methodology using the modified average stress fracture criterion is developed for predicting the failure of notched composites containing localised waviness. The approach can be used to assess the quality of a given processing technique for the manufacturing of the composite system.
LeeJ, SoutisC: ‘A study on the compressive strength of thick carbon fibre–epoxy laminates’, J. Aerosp. Eng., 2007, 67, (10), 2015–2016.
3.
HsiaoHM, DanielIM: ‘Effect of fiber waviness on stiffness and strength reduction of unidirectional composites under compressive loading’, Compos. Sci. Technol., 1996, 56, (5), 581–593.
4.
HsiaoHM, DanielIM: ‘Nonlinear elastic behavior of unidirectional composites with fiber waviness under compressive loading’, J. Eng. Mater. Technol., 1996, 118, (4), 561–570.
5.
ChunH, ShinJ, DanielIM: ‘Effects of material and geometric nonlinearities on the tensile and compressive behavior of composite materials with fiber waviness’, Compos. Sci. Technol., 2001, 61, (1), 125–134.
6.
JoycePJ, KuglerD, MoonTJ: ‘A technique for characterizing process-induced fiber waviness in unidirectional composite laminates using optical microscopy’, J. Compos. Mater., 1997, 31, (17), 1694–1727.
7.
BarberoEJ: ‘Prediction of compressive strength of unidirectional polymer matrix composites’, J. Compos. Mater., 1998, 32, (5), 483–502.
8.
DavisJG: ‘Compressive strength of fiber reinforced composite materials’, in ‘Composite reliability’, ASTM Spec. Tech. Publ., 1975, 580, 364–377.
9.
RosenBW: ‘Mechanics of composite strengthening’, in‘Fiber composite materials’, (ed. , BushS H), Chapter 3, 37–75; 1965, Metals Park, OH, ASM.
10.
BogettiTA, GillespieJW, LamontiaMA: ‘Influence of ply waviness on the stiffness and strength reduction on composite laminates’, J. Thermoplast. Compos. Mater., 1992, 5, (4), 344–369.
11.
AdamsDO, HyerMW: ‘Effects of layer waviness on the compression fatigue performance of thermoplastic composite laminates’, Int. J. Fatigue, 1994, 16, (6), 385–392.
12.
KaramiG, GarnichM: ‘Effective moduli and failure considerations for composites with periodic waviness’, Compos. Struct., 2005, 67, (4), 461–475.
13.
PotterK, KhanB, WisnomM, BellT, StevensJ: ‘Variability, fibre waviness and misalignment in the determination of the properties of composite materials and structures’, Composites A, 2008, 39A, (9), 1343–1354.
14.
WisnomMR, AtkinsonJW: ‘Fiber waviness generation and measurement and its effect on compressive strength’, J. Reinf. Plast. Compos., 2000, 19, (2), 96–110.
15.
El-HajjarRF, PetersenDR: ‘Gaussian function characterization of unnotched tension behavior in a carbon/epoxy composite containing localized fiber waviness’, Compos. Struct., 2011, 93, (9), 2400–2408.
16.
CaiazzoA, OrletM, McShaneH, StraitL, RachauC: ‘The effects of Marcel defects on composite structural properties’, in‘Composite structures: theory and practice’, (ed. , GrantP, RousseauC Q), 158–187, ASTM STP 1383; 2000, West Conshohocken, PA, USA, ASTM.
17.
SawickiAJ, MinguetPJ: ‘The effect of intraply overlaps and gaps upon the compression strength of composite laminates’, ‘Collection of technical papers – AIAA/ASME/ASCE/SHS/ASC structures’, Proc. Structural Dynamics & Materials Conf., Denver, CO, USA, April 1998, The American Institute of Aeronautics and Astronautics, 744–754.
18.
BradleyDJ, AdamsDO, GascoigneHE: ‘Interlaminar strains and compressive strength reductions due to nested layer waviness in composite laminates’, J. Reinf. Plast. Compos., 1998, 17, (11), 989–1011.
19.
HashinZ, RotemA: ‘A fatigue failure criterion for fiber-reinforced materials’, J. Compos. Mater., 1973, 7, 448.
20.
PansartS, SinapiusM, GabbertU: ‘A comprehensive explanation of compression strength differences between various CFRP materials: micro–meso model, predictions, parameter studies’, Composites A, 2009, 40A, (4), 376–387.
21.
TomblinJ, SherradenJ, SeneviratneW, RajuKS: ‘Advanced general aviation transport experiments. A – basis and b – basis design allowables for epoxy-based prepreg TORAY T700GC-12K-31E/#2510 unidirectional tape’, Report no.AGATE-WP3·3-033051-132, National Institute for Aviation Research, Wichita State University, Wichita, KS, USA, 2002.
22.
LekhnitskiiSG: ‘Theory of elasticity of an anisotropic body’; 1963, San Francisco, CA, Holden-Day.
23.
WhitneyJM, NuismerRJ: ‘Stress fracture criteria for laminated composites containing stress concentrations’, J. Compos. Mater., 1974, 8, 253–265.
24.
DanielIM, IshaiO: ‘Engineering mechanics of composite materials’, 2nd edn; 2006, New York, Oxford University Press.
25.
TanSC: ‘Stress concentrations in laminated composites’; 1994, Lancaster, PA, Technomic.
26.
‘D5766/D5766M-02a standard test method for open hole tensile strength of polymer–matrix composite laminates’, ‘Composite materials’, Vol. 15.03, ASTM International, West Conshohocken, PA, USA, 2007.
27.
‘Standard test method for tensile properties of polymer matrix composite materials’, D3039/D3039M, American Society of Testing and Materials, West Conshohocken, PA, USA, 2008.
28.
MakeevA, SeonG, LeeE: ‘Failure predictions for carbon/epoxy tape laminates with wavy plies’, J. Compos. Mater., 2010, 44, 95–112.
