The impact damage resistance of carbon fibre/epoxy matrix composites containing short Kevlar® fibres as the interlayer material was studied. Instrumented low-velocity impact tests were conducted at several temperatures to study the impact fracture and damage mechanisms. The experimental results indicate that short Kevlar fibres improved the impact damage performance. Distinct damage patterns were observed on the front and back faces of the specimens tested at two extreme temperatures; -60°C and 130°C. Cross-sectional microscopy was performed to evaluate sub-surface damage; optical and scanning electron microscopy were used to study the fracture mechanisms of the laminates impacted at different temperatures. The main contribution of the interlayer material to the improvement in impact resistance was the enhanced fibre-bridging with the short Kevlar fibres at the interlaminar regions.
References
1.
RussellA.J., and StreetK.N., “Moisture and temperature effects on the mixed-mode delamination fracture of unidirectional graphite/epoxy”, ASTMSTP876, JohnsonW.S., Ed., American Society for Testing and Materials, Philadelphia, (1985), 349–370.
2.
BiboG., LeicyP.J., and KempM., “High-temperature damage tolerance of carbon fibre-reinforced plastics – Part 1: Impact characteristics”, Composites, 25 (1994), 414–424.
3.
BiboG.A., and HoggP.J., “High-temperature damage tolerance of carbon fibre-reinforced plastics – Part 2: Post-impact compression characteristics”, Composites, 26, (1995), 91–102.
4.
DaviesP., and BenzeggaghM.L., “Interlaminar mode I fracture testing. In Applications of Fracture Mechanics to Composite Materials”, ed. FriedrichK.Elsevier Science, Amsterdam, (1989) 81–112
5.
HashemiS., KinlochA.J., and WilliamsJ.G., “The effects of geometry, rate and temperature on the mode I, mode II and mixed I/II interlaminar fracture of carbon fibre/PEEK composites”, J. Compos. Sci. Technol., 43 (1992) 37–47
6.
KarasekM.L., StraitL.H., AmateauM.F., and RuntJ.P., “Effect of temperature and moisture on the impact behaviour of graphite/epoxy composites: Part II – Impact Damage”J. Comp. Tech. & Res.17(1) (1995) 11–16
7.
BouadiH., & SunC.T., “Hygrothermal effects on structural stiffness and structural damping of laminated composites”, J. Mater. Sci., 25 (1990) 499–505
8.
KellasS., MortonJ., & CurtisP.T., “The effect of hygrothernal environments upon the tensile and compressive strengths of notched CFRP laminates. Part 1: Static loading”, Composites, 21 (1990) 41–51
9.
BirgerS., MoshonovA., and KenigS., “The effects of thermal and hygrothermal ageing on the failure mechanisms of graphite-fabric epoxy composites subjected to flexural loading”, Composites, 20 (1989) 341–348
10.
LevinK., “Effect of low-velocity impact on compression strength of quasi-isotropic laminate”. In Proceedings of American Society for Composites: 1st Technical Conference. Technomic, Lancaster, PA (1986) 313–325
11.
LagaceP.A., “Delamination in composites: is toughness the key?”31st International SAMPE Symposium, April 7-10 (1986) 738–749
12.
KesslerA., and BledzkiA.K., “Low velocity impact behaviour of glass/epoxy cross-ply laminates with different fibre treatments”, Polym. Com.20(2) (1999) 269–278
13.
HiraiY., HamadaH., and KimJ.K., “Impact response of woven glass-fabric composites - I. Effect of fibre surface treatment”, Comp. Sci. & Tech.58 (1998) 91–104
14.
MastersJ.E., “Improved impact and delamination resistance through interleafing”, Key Eng. Mater.37 (1989) 317–348
15.
LuW.H., LiaoF.S., SuA.C., KaoP.W., HsuT.J., “Effect of interleaving on the impact response of a unidirectional carbon/epoxy composite”, Composites26(3) (1995) 215–222
16.
RechakS., and SunC.T., “Optimal use of adhesive layers in reducing impact damage in composite laminates”, J. Rein. Plast. & Comp.9 (1990) 569–582
17.
IshaiO., RosenthalH., SelaN., and DrukkerE., “Effect of selective adhesive interleaving on interlaminar fracture toughness of graphite/epoxy composite laminates”, Composites19 (1988) 49–54
18.
PoonC., BenakT., and GouldR., “Assessment of impact damage in toughened resin composites”Theo. & Appl. Frac. Mech., 13 (1990) 81–97
19.
StraitL.H., KarasekM., and AmateauM.F., “Effects of stacking sequence on the impact resistance of fibre reinforced thermoplastic toughened epoxy laminates”, J. Mater. Sci.26(2) (1992) 1725–1740
20.
JangB.Z., ChenL.C., WangC.Z., & LinH.T., “Impact resistance and energy absorption mechanisms in hybrid composites”, Comp. Sci. & Tech.34 (1989) 305–33
21.
DoreyG., SideyG.R., and HutchingsJ., “Impact properties of carbon fibre/Kevlar 49 fibre hybrid composites”, Composites9 (1978) 25–36
22.
JangJ., and MoonS.I., “Impact behaviour of carbon fibre/ultra-high modulus PE fibre hybrid composites”, Polym. Comp.16 (4) (1995) 325–239
SohnM.S., and HuX.Z., “Comparative study of dynamic and static delamination behaviour of carbon fibre/epoxy composite laminates”, Composites26 (1995) 849–858
25.
SohnM.S., and HuX.Z., “Unidirectional carbon fibre/epoxy laminates interleaved by film adhesives and chopped Kevlar fibres”, Key Eng. Mat.145-149 (1998) 727–732
26.
FarleyG.L., SmithB.T., and MaidenJ., “Compression response of thick composite laminates with through-the-thickness reinforcement”, J. Reinf. Plast. Comp.11 (1992) 787–810
27.
KimJ.K., “Methods for improving impact damage resistance of CFRPs”, Key Eng. Mat.141-143 (1998) 149–168
28.
HiraiY., HamadaH., and KimK., “Impact response of woven glass-fabric composites – II. Effect of temperature”, Comp. Sci. & Tech.58 (1998) 119–128
29.
BowlesK.J., “The correlation of low-velocity impact resistance of glass fibre reinforced composites with matrix properties.” In Composite materials: Testing and Design (8th Conference), ASTM STP 972, ed. WhitcombJ.D.American Society for Testing and Materials, Philadelphia, PA, (1988) 124–142
30.
SohnM.S., HuX.Z., KimJ.K., and WalkerL., “Impact damage characterisation of carbon fibre/epoxy composites with multi-layer reinforcement”, Composites B, 31 (2000) 681–691
31.
WalkerL., and HuX.Z., “Limitations to fracture toughness increase in short fibre reinforced carbon-fibre composite due to intra-ply cracking”, Proceedings of International Workshop on Fracture Mechanics and Advanced Engineering Materials, 8-10 December (1999) 345–351
