In this study, the effect of carboxyl-terminated butadiene-acrylonitrile liquid rubber on fracture toughness of glass-reinforced epoxy composites has been investigated. Fracture toughness tests were conducted in modes I, II and different mixed mode ratios. The data obtained from these tests have been analyzed by using different methods. Results indicated that interlaminar fracture toughness of composite specimens improved considerably through addition of carboxyl-terminated butadiene-acrylonitrile in modes I, II and mixed mode. Interlaminar fracture surfaces of the specimens were also characterized by field emission scanning electron microscope.
YumYJYouH. Pure mode I, II and mixed mode interlaminar fracture of graphite/epoxy composite materials. J Reinf Plast Compos2001; 20: 794–808.
3.
YehHYKimCH. The mixed mode fracture analysis of unidirectional composites. J Reinf Plast Compos1994; 13: 498–508.
4.
LeeDBIkedaTMiyazakiN. Damage zone around crack tip and fracture toughness of rubber-modified epoxy resin under mixed-mode conditions. Eng Fract Mech2002; 69: 1363–1375.
5.
PearsonRAYeeAF. Influence of particle size and particle size distribution on toughening mechanisms in rubber-modified epoxies. J Mater Sci1991; 26: 3828–3844.
6.
BagheriRPearsonRA. Role of particle cavitation in rubber-toughened epoxies, part I: microvoid toughening. Polymer1996; 37: 4529–4538.
7.
TracyGDFeraboliPKedwardKT. A new mixed mode test for carbon/epoxy composite systems. Compos A2003; 34: 1125–1131.
8.
Marat-MendesRFreitasM. Failure criteria for mixed mode delamination in glass fibre epoxy composites. Compos Struct2010; 92: 2292–2298.
9.
Marat-Mendes R and Freitas M. DCB, ENF and ECT tests for interlaminar fracture of glass/epoxy unidirectional laminates. In: Proceedings of 10th Portuguese conference on fracture, Guimarles, Portugal, 2006, pp. 22–24. Guimarães, Portugal: University of Minho.
10.
Marat-Mendes R and Freitas M. Mode I, mode II, mode III and mixed mode interlaminar fracture of glass/epoxy unidirectional laminates. In: Proceedings of EUROMECH 473 conference, Porto, Portugal, October 2005, pp. 27–29.
11.
WilliamsJG. End correction for orthotropic DCB specimens. Compos Sci Technol1989; 35: 367–376.
12.
WangYWilliamJG. Corrections for mode II fracture-toughness specimens of composites materials. Compos Sci Technol1992; 43: 251–256.
DuceptFDaviesPGambyD. Mixed mode failure criteria for a glass/epoxy composite and an adhesively bonded composite/composite joint. Int J Adhes Adhes2000; 20: 233–244.
16.
MathewsMJSwansonSR. Characterization of the interlaminar fracture toughness of a laminated carbon/epoxy composite. Comp Sci Tech2007; 67: 1489–1498.
17.
ReederJR. An evaluation of mixed-mode delamination failure criteria, Hampton, VA: NASA Technical Memorandum 104210, Langley Research Center, 1992.
18.
ASTM D 5528. Standard test method for mode I interlaminar fracture toughness of unidirectional fiber-reinforced polymer matrix composites [Annual book of ASTM standards], West Conshohocken, PA: ASTM, 2001.
19.
ASTM D 6671/D 6671M. Standard test method for mixed mode I-mode II interlaminar fracture toughness of unidirectional fiber reinforced polymer matrix composites [Annual book of ASTM standards], West Conshohocken, PA: ASTM, 2001.
20.
Agastra P. Mixed mode delamination of glass fiber/polymer matrix composite materials. A thesis submitted in partial fulfillment of the requirements for the degree of Master of Science in Chemical Engineering, Bozeman, Montana, March 2004.
21.
CrewsJHReederJR. A mixed mode bending apparatus for delamination testing, Hampton, VA: NASA TM-100662, 1988, pp. 19–31.
22.
ReederJRCrewsJH. The mixed mode bending method for delamination testing. AIAA J1990; 28: 1270–1276.
23.
ReederJRCrewsJH. Nonlinear analysis and redesign of the mixed mode bending delamination test, Hampton, VA: NASA TM-102777, 1991, pp. 18–32.
24.
ASTM D 3039/D 3039M. Standard test method for tensile properties of polymer matrix composite materials [Annual book of ASTM standards], West Conshohocken, PA: ASTM, 2008.
25.
DadfarMRGhadamiF. Effect of rubber modification on fracture toughness properties of glass reinforced hot cured epoxy composite. Mater Des2013; 47: 16–20.
26.
BarberoEJ. Introduction to composite materials design, 2nd ed. New York: CRC Press, 2010, pp. 154–154.
27.
CarlssonLAGillespieJWMode II interlaminar fracture of composites. In: FriedrichK (ed). Application of fracture mechanics to composite materials, Amsterdam: Elsevier, 1989, pp. 113–157.
28.
KimBWMayerAH. Influence of fiber direction and mixed-mode ratio on delamination fracture toughness of carbon/epoxy laminates. Compos Sci Technol2003; 63: 695–713.
29.
ErdenSSeverKSekiK. Enhancement of the mechanical properties of glass/polyester composites via matrix modification glass/polyester composite siloxane matrix modification. Fibers Polym2010; 11: 732–737.
30.
WosuSNHuiDDuttaPK. Dynamic mixed-mode I/II delamination fracture and energy release rate of unidirectional graphite/epoxy composites. Eng Fract Mech2005; 72: 1531–1558.
