The purpose of this study was to determine the influence of fibre architectures on the interlaminar fracture toughness and tensile toughness of flax fibre epoxy composites. The fracture toughness was investigated for both Mode I (GIC) and Mode II (GIIC) for seven flax-epoxy architectures: one plain weave, two twill 2 × 2 weaves, a quasi-unidirectional and a unidirectional architecture, the UD’s being tested in both [0,90] and [90,0] composite lay-ups. The results of the Mode I and Mode II showed promising results of the flax-epoxy composite performance. The addition of flax fibre increases the GIC and GIIC of the composites over that of the unreinforced brittle polymer by at least two to three times. Further improvements are made with the use of woven textiles. The tensile toughness was found to be a good indicator of the capacity of a material to sustain perforation or non-perforation impact.
MaJQiQBayleyJ. Development of SENB toughness measurement for thermoset resins. Polym Test2007; 26: 445–450.
5.
CheremisinoffN. Handbook of ceramics and composites: Mechanical properties and specialty applications1991; Vol. 2, NYC, USA: CRC Press, pp. 528–528.
6.
SchrauwenBPeijsT. Influence of matrix ductility and fibre architecture on the repeated impact response of glass-fibre-reinforced laminated composites. Appl Compos Mater2002; 9: 331–352.
7.
CantwellWJMortonJ. The impact resistance of composite materials – a review. Composites1991; 22: 347–362.
8.
DhakalHNSkrifvarsMAdekunleK. Falling weight impact response of jute/methacrylated soybean oil bio-composites under low velocity impact loading. Compos Sci Technol2014; 92: 134–141.
9.
LiuQHughesM. The fracture behaviour and toughness of woven flax fibre reinforced epoxy composites. Compos Part A2008; 39: 1644–1652.
10.
MouritzA. Review of z-pinned composite laminates. Compos Part A2007; 38: 2383–2397.
11.
RongMZZhangMQLiuY. Effect of stitching on in-plane and interlaminar properties of sisal/epoxy laminates. J Compos Mater2002; 36: 1505–1526.
12.
MouritzABannisterMFalzonP. Review of applications for advanced three-dimensional fibre textile composites. Compos Part A1999; 30: 1445–1461.
13.
SingletonACNBaillieCABeaumontPWR. On the mechanical properties, deformation and fracture of a natural fibre/recycled polymer composite. Compos Part B2003; 34: 519–526.
14.
KimBHJoeCROttersonDM. On the determination of fracture toughness in polymers. PolymTest1988; 8: 119–130.
15.
ArencónDVelascoJI. Fracture toughness of polypropylene-based particulate composites. Materials2009; 2: 2046–2094.
16.
DuceptFDaviesPGambyD. An experimental study to validate tests used to determine mixed mode failure criteria of glass/epoxy composites. ComposPart A1997; 28: 719–729.
DaviesPKauschHHWilliamsJG. Round-robin interlaminar fracture testing of carbon-fibre-reinforced epoxy and PEEK composites. Compos Sci Technol1992; 43: 129–136.
19.
DaviesPMoulinCKauschH. Measurement of G IC and G IIC in carbon/epoxy composites. Compos Sci Technol1990; 39: 193–205.
20.
ZhuY. Characterization of interlaminar fracture toughness of a carbon/epoxy composite material, Master thesis, The Pennsylvania State University, State College, 2009.
21.
SheddenJ. Simplifying the testing and calculation of fracture toughness of thermoplastic and thermoset matrix composite materials, Bachelor Thesis, The Faculty of the Materials Engineering Department, San Luis Obispo California Polytechnic State University, 2013.
22.
CowleyKDBeaumontPW. The interlaminar and intralaminar fracture toughness of carbon-fibre/polymer composites: the effect of temperature. Compos Sci Technol1997; 57: 1433–1444.
23.
HashemiSKinlochAWilliamsJ. The analysis of interlaminar fracture in uniaxial fibre-polymer composites. Proc R Soc Lond A1990; 427: 173–199.
24.
ZahlanN. Mechanical properties of the carbon fiber/PEEK composite APC-2/AS-4 for structural applications, Philadelphia: American Society for Testing and Materials Special Technical Publication, 1989, pp. 199–199.
25.
Davidson BD, Altonen CS and Polaha JJ. Effect of stacking sequence on delamination toughness and delamination growth behavior in composite end-notched flexure specimens. vol. 1274, West Conshohocken, PA, USA: ASTM Special Technical Publication, 1996, pp.393–413.
26.
TanakaKKageyamaKHojoM. Prestandardization study on mode II interlaminar fracture toughness test for cfrp in japan. Composites1995; 26: 257–267.
27.
ChamisCCHansonMPSerafiniTT. Impact resistance of unidirectional fiber composites. Composite materials: Testing and design; Second Conference, Anaheim, CA, 20–22 April 1971.
28.
RoylanceD. Stress-strain curves, Cambridge: Massachusetts Institute of Technology study, 2001.
29.
Bensadoun F, Depuydt D, Baets J, et al. Impact resistance, damage and absorbed energy behaviour of flax-based composites. Composite week @ Leuven Leuven (Belgium), 2013, https://lirias.kuleuven.be/handle/123456789/428911.
30.
Bensadoun F, Depuydt D, Baets J, et al. Influence of fibre architecture on impact and fatigue behaviour of flax fibre-based composites. In: 19th International conference on composite materials (ICCM19), Montreal, Quebec, Canada, 28 July–2 August 2013.
31.
Decorme J, Duval A, Vanfleteren E, et al. Method for producing a continuous web of fibers comprising long natural fibers, and associated apparatus and web. Patent US 20140287216 A1, 2012.
32.
BensadounFVallonsKALessardLB. Fatigue behaviour assessment of flax-epoxy composites. Compos Part A2016; 82: 253–266–253–266.
33.
Standard A. D5528-94a. Standard test method for mode I interlaminar fracture toughness of unidirectional continuous fiber reinforced polymer matrix composites. Philadelphia, PA, USA, 1994.
Reeder J, Allen D and Bradley W. Effect of elevated temperature and loading rate on delamination fracture toughness. ICCM 14th International Conference on Composite Materials, San Diego, CA, United States, 14–18 July 2003.
36.
Blackman B, Williams J and Benguediab M. Crack length determination difficulties in composites-their effect on toughness evaluation. 11th International Conference on Fracture (ICF11), Turin, Italy, 20–25 March 2005.
37.
BlackmanBRKKinlochAJParaschiM. Measuring the mode I adhesive fracture energy, GIC, of structural adhesive joints: the results of an international round-robin. Int J Adhes Adhes2003; 23: 293–305.
38.
ZhuX-KJoyceJA. Review of fracture toughness (G, K, J, CTOD, CTOA) testing and standardization. Eng Fract Mech2012; 85: 1–46.
39.
OlaveMVaraIHusabiagaH. Nesting effect on the mode I fracture toughness of woven laminates. Compos Part A2015; 74: 166–173.
40.
YoshiharaH. Mode I and mode II initiation fracture toughness and resistance curve of medium density fiberboard measured by double cantilever beam and three-point bend end-notched flexure tests. Eng Fract Mech2010; 77: 2537–2549.
41.
LaksimiABenzeggaghMLJingG. Mode I interlaminar fracture of symmetrical cross-ply composites. Compos Sci Technol1991; 41: 147–164.
42.
MelcherRJJohnsonWS. Mode I fracture toughness of an adhesively bonded composite–composite joint in a cryogenic environment. Compos Sci Technol2007; 67: 501–506.
43.
Blackman B and Kinloch A. Protocol for the determination of the Mode I adhesive fracture energy, GIc, of structural adhesives using the double cantilever beam (DCB) and tapered double cantilever beam (TDCB) specimens. Version 00-08 European Structural Integrity Society Polymers, Adhesives and Composites TC4 Committee, 2000.
44.
De MouraMCampilhoRAmaroA. Interlaminar and intralaminar fracture characterization of composites under mode I loading. Compos Struct2010; 92: 144–149.
45.
AravandMLomovSVGorbatikhL. Morphology and fracture behavior of POM modified epoxy matrices and their carbon fiber composites. Compos Sci Technol2015; 110: 8–16.
KimK-YCuriskisJIYeL. Mode-I interlaminar fracture behaviour of weft-knitted fabric reinforced composites. Compos Part A2005; 36: 954–964.
50.
KalarikkalSG. Fracture toughness of graphite/epoxy laminates at cryogenic conditions, Master thesis, University of Florida, Gainesville, 2004.
51.
RheeKYKohSKLeeJH. Mode I fracture resistance characteristics of graphite/epoxy laminated composites. Polym Compos2000; 21: 155–164.
52.
de MoraisABde MouraMFMarquesAT. Mode-I interlaminar fracture of carbon/epoxy cross-ply composites. Compos Sci Technol2002; 62: 679–686.
53.
OBrienTK. Composite interlaminar shear fracture toughness, GIIC: shear measurement of sheer myth?Composite Materials: Fatigue and Fracture1997; Vol. 7, West Conshohocken, PA, USA: ASTM International.
54.
Lens LN, Bittencourt E and d'Avila VMR. Constitutive models for cohesive zones in mixed mode. In: 20th. International Congress of Mechanical Engineering, Vol. 20, Gramado, 2009, pp.1–8.
55.
DillardDASinghHKPohlitDJ. Observations of decreased fracture toughness for mixed mode fracture testing of adhesively bonded joints. J Adhes Sci Technol2009; 23: 1515–1530.
56.
RoylanceD. Introduction to fracture mechanics, Cambridge: Massachusetts Institute of Technology, 2001.
57.
GillespieJWJrCarlssonLAPipesRB. Finite element analysis of the end notched flexure specimen for measuring mode II fracture toughness. ComposSci Technol1986; 27: 177–197.
58.
WangJQiaoP. Novel beam analysis of end notched flexure specimen for mode-II fracture. Eng Fract Mech2004; 71: 219–231.
59.
ZureickA-HNettlesAT. Composite materials: testing, design, and acceptance criteria. ASTM International (STP 1416)2002; Vol. 1416, , West Conshohocken, PA, USA.
60.
TaminMN. Damage and fracture of composite materials and structures, Heidelberg, Germany: Springer, 2012.
