A thermosetting epoxy-polymer was modified by incorporating 9 wt% of carboxyl-terminated butadiene-acrylonitrile rubber microparticles and 10 wt% of silica nanoparticles. The tensile fatigue behavior at a stress ratio, R = 0.1 for both the neat-epoxy polymer (i.e., unmodified) and the hybrid-epoxy polymer was first investigated. The fatigue life of the hybrid-epoxy polymer was about six to ten times higher than that of the neat-epoxy polymer. Secondly, the neat- and the hybrid-epoxy resins were infused into a quasi-isotropic lay-up, E-glass fiber fabric via a ‘Resin Infusion under Flexible Tooling’ set-up to fabricate glass-fiber reinforced plastic (GFRP) composite panels. The tensile fatigue tests at a stress ratio, R = 0.1 were performed on both of these GFRP composites during which the matrix cracking and stiffness degradation were routinely monitored. The fatigue life of the GFRP composite increased by about six to ten times due to employing the hybrid-epoxy matrix, compared to employing the neat-epoxy matrix. Suppressed matrix cracking and a reduced crack propagation rate were observed in the hybrid-epoxy matrix, which resulted from the various toughening micromechanisms induced by the presence of both the rubber microparticles and silica nanoparticles. These factors were considered to contribute towards the enhanced fatigue life which was observed for the GFRP composite employing the hybrid-epoxy matrix.
Kinloch, A.J. , Mohammed, R.D., Taylor, A.C., Eger, C., Sprenger, S. and Egan, D. (2005). The Effect of Silica Nano Particles and Rubber Particles on the Toughness of Multiphase Thermosetting Epoxy Polymers, J. Mater. Sci., 40(18): 5083-5086.
2.
Fu, S.Y. , Feng, X.Q., Lauke, B. and Mai, Y.W. (2008). Effects of Particle Size, Particle/Matrix Interface Adhesion and Particle Loading on Mechanical Properties of Particulate-Polymer Composites, Compos. Part B, 39: 933-961.
3.
Johnsen, B.B. , Kinloch, A.J., Mohammed, R.D., Taylor, A.C. and Sprenger, S. (2007). Toughening Mechanisms of Nanoparticle-modified Epoxy Polymers, Polymer, 48(2): 530-541.
4.
Ma, J., Mo, M.S., Du, X.S., Rosso, P., Friedrich, K. and Kuan, H.C. ( 2008). Effect of Inorganic Nanoparticles on Mechanical Property, Fracture Toughness and Toughening Mechanism of Two Epoxy Systems, Polymer, 49: 3510-3523.
5.
Kinloch, A.J. , Mohammed, R.D., Taylor, A.C., Sprenger, S. and Egan, D.J. (2006). The Interlaminar Toughness of Carbon Fiber Reinforced Plastic Composites Using Hybrid Toughened Matrices , J. Mater. Sci., 41(15): 5043-5046.
6.
Chisholm, N. , Mahfuz, H., Rangari, V.K., Ashfaq, A. and Jeelani, S. (2005). Fabrication and Mechanical Characterization of Carbon/SiC-epoxy Nanocomposites, Compos. Struct., 67: 115-124.
7.
Kinloch, A.J. , Masania, K., Taylor, A.C., Sprenger, S. and Egan, D. (2008). The Fracture of Glass Fiber-reinforced Epoxy Composites Using Nanoparticle Modified Matrices, J. Mater. Sci., 43(3): 1151-1154.
8.
Zheng, Y., Zheng, Y. and Ning, R. ( 2003). Effects of Nanoparticles SiO2 on the Performance of Nanocomposites, Mater. Lett., 57: 2940-2944.
9.
Gojny, F.H., Wichmann, M.H.G., Fiedler, B., Bauhofer, W. and Schulte, K. ( 2005). Influence of Nano-modification on the Mechanical and Electrical Properties of Conventional Fiber-reinforced Composites, Compos . Part A, 36: 1525-1535.
10.
Zhou, Y., Pervin, F., Jeelani, S. and Mallick, P.K. ( 2008). Improvement in Mechanical Properties of Carbon Fabric-epoxy Composite Using Carbon Nanofibers, J. Mater. Process. Tech. , 198: 445-453.
11.
Haque, A., Shamsuzzoha, M., Hussain, F. and Dean, D. ( 2003). S2-Glass/Epoxy Polymer Nanocomposites: Manufacturing, Structures, Thermal and Mechanical Properties, J. Compos. Mater., 37(20): 1821-1837.
12.
Zhou, Y., Rangari, V., Mahfuz, H., Jeelani, S. and Mallik, P.K. ( 2005). Experimental Study on Thermal and Mechanical Behaviour of Polypropylene, Talc/Polypropylene and Polypropylene/ Clay Nanocomposites, Mater. Sci. Eng. A, 402: 109-117.
13.
Manjunatha, C.M. , Taylor, A.C., Kinloch, A.J. and Sprenger, S. (2009). The Tensile Fatigue Behaviour of a GFRP Composite with Rubber Particle Modified Epoxy Matrix, J. Reinf. Plast. Comp., DOI: 10.1177/1056789506069473.
14.
Manjunatha, C.M., Taylor, A.C., Kinloch, A.J. and Sprenger, S. (2009). The Effect of Rubber Micro-particles and Silica Nano-particles on the Tensile Fatigue Behaviour of a Glass Fiber Epoxy Composite, J. Mater. Sci., 44: 342-345.
15.
Summerscales, J. and Searle, T.J. (2005). Low-pressure (Vacuum Infusion) Techniques for Moulding Large Composite Structures, Proc. IMechE, Part L, J. Mater: Des Appl., 219: 45-58.
16.
Astm (2003). Standard Test Method for Tensile Properties of Plastics, ASTM D638-01, Annual Book of ASTM Standards, Vol. 8.02, American Society for Testing and Materials, PA.
17.
Astm (2003). Standard Test Method for Tensile Properties of Polymer Matrix Composite Materials , ASTM D3039, Annual Book of ASTM Standards, Vol. 15.03, American Society for Testing and Materials, PA.
18.
Astm (2003). Standard Test Method for Tension-Tension Fatigue of Polymer Matrix Composite Materials, ASTM D3479M-96, Annual Book of ASTM Standards, Vol. 8.02, American Society for Testing and Materials, PA.
19.
Mandell, J.F. and Meier, U. (1983). Effect of Stress Ratio, Frequency and Loading Time on the Tensile Fatigue of Glass-reinforced Epoxy , In: O’Brien, T.K. (ed.), Long-term Behaviour of Composites, ASTM STP 813, pp. 55-77, ASTM International, West Conshohocken, PA.
20.
Staff, C.R. ( 1983). Effect of Load Frequency and Lay-up on Fatigue Life of Composites, In: O’Brien, T.K. (ed.), Long-term Behaviour of Composites, ASTM STP 813, pp. 78-91, ASTM International, West Conshohocken, PA.
21.
Sun, C.T. and Chan, W.S. (1979). Frequency Effect on the Fatigue Life of a Laminated Composite, In: Tsai, S.W. (ed.), Composite Materials: Testing and Design (Fifth Conference), ASTM STP 674, pp. 418-430, ASTM International, West Conshohocken, PA.
22.
Lee, J. , Fu, K.E. and Yang, J.N. (1996). Prediction of Fatigue Damage and Life for Composite Laminates Under Service Loading Spectra, Comp . Sci. Tech., 56: 635-648.
23.
Gagel, A., Lange, D. and Schulte, K. ( 2006). On the Relation between Crack Densities, Stiffness Degradation and Surface Temperature Distribution of Tensile Fatigue Loaded Glass-fiber Non-crimp-fabric Reinforced Epoxy, Compos. Part A, 37: 222-228.
24.
Buch, A. ( 1988). Fatigue Strength Calculation, Transtech Publications, Switzerland.
Arias, M.L. , Frontini, P.M. and Williams, R.J.J. (2003). Analysis of the Damage Zone around the Crack Tip for Two Rubber-modified Epoxy Matrices Exhibiting Different Toughenability, Polymer, 44(5): 1537-1546.
27.
Pearson, R.A. and Yee, A.F. (1991). Influence of Particle Size and Particle Size Distribution on Toughening Mechanisms in Rubber Modified Epoxies, J. Mater. Sci., 26(14): 3828-3844.
28.
Azimi, H.R., Pearson, R.A. and Hertzberg, R.W. ( 1996). Fatigue of Rubber-modified Epoxies: Effect of Particle Size and Volume Fraction, J. Mater. Sci., 31(14): 3777-3789.
29.
Low, I.M. and Mai, Y.W. (1988). Micromechanisms of Crack Extension in Unmodified and Modified Epoxy Resins, Compos. Sci. Tech., 33(3): 191-212.
30.
Lowe, A., Kwon, A.H. and Mai, Y.W. ( 1996). Fatigue and Fracture Behavior of Novel Rubber Modified Epoxy Resins, Polymer, 37(4): 565-572.
31.
Imanaka, M., Motohashi, S., Nishi, K., Nakamura, Y. and Kimoto, M. ( 2009). Crack-growth Behaviour of Epoxy Adhesives Modified with Liquid Rubber and Cross-linked Rubber Particles Under Mode I Loading, Int. J. Adhes. Adhes., 29(1): 45-55.
32.
Caccavale, V., Wichmann, M.H.G., Quaresimin, M. and Schulte, K. ( 2007). Nanoparticle/ Rubber Modified Epoxy Matrix Systems: Mechanical Performance in CFRPs, In: AIAS XXXVI Convegno Nazionale , 4-8 September, Ischia, Napoli.
33.
Blackman, B.R.K. , Kinloch, A.J., Sohn Lee, J., Taylor, A.C., Agarwal, R., Schueneman, G. and Sprenger, S. (2007). The Fatigue and Fracture Behaviour of Nano-modified Epoxy Polymers, J. Mater. Sci. , 42: 7049-7051.
34.
Rosso, P., Ye, L., Friedrich, K. and Sprenger, S. ( 2006). A Toughened Epoxy Resin by Silica Nanoparticle Reinforcement , J. Appl. Polym. Sci., 100(3): 1849-1853.
35.
Zhang, H., Zhang, Z., Friedrich, K. and Eger, C. ( 2006). Property Improvements of In Situ Epoxy Nanocomposites with Reduced Interparticle Distance at High Nanosilica Content, Acta Mater., 54(7): 1833-1842.
36.
Talreja, R. (1989). Fatigue of Composite Materials: Damage Mechanisms and Fatigue Life Diagrams, Proc. Roy. Soc. Lon. A, 378: 559-567.
37.
Hahn, H.T. and Kim, R.Y. ( 1976). Fatigue Behaviour of Composite Laminates, J. Comp. Mater., 10: 156-180.
38.
Case, S.W. and Reifsnider, K.L. ( 2003). Fatigue of Composite Materials, In: Milne, I., Ritchie, R.O. and Karihaloo, B. (eds), Comprehensive Structural Integrity: Vol. 4: Cyclic Loading and Fatigue, 1st edn, Elsevier Science, Amsterdam.
39.
Tate, J.S. and Kelkar, A.D. ( 2008). Stiffness Degradation Model for Biaxial Braided Composites Under Fatigue Loading, Compos. Part B, 39(3): 548-555.
40.
Reifsnider, K.L. and Jamison, R. (1982). Fracture of Fatigue-loaded Composite Laminate, Int. J. Fatigue, 4(4): 187-197.
41.
Li, C., Ellyin, F. and Wharmby, A. ( 2003). On Matrix Crack Saturation in Composite Laminates, Compos . Part B, 34: 473-480.
42.
Case, S.W., Caliskan, A., Iyengar, N. and Reifsnider, K.L. ( 1996). Performance Simulation of High-temperature Polymeric Composite Materials using MR Life, In: Proceedings of ASME, Aerospace Division - 1996 ASME International Mechanical Engineering Congress and Exposition, Atlanta, Georgia, USA, pp. 375-380.
43.
Reifsnider, K. (1980). Fatigue Behaviour of Composite Materials, Int. J. Fracture, 16(6): 563-583.
44.
Wharmby, A.W. , Ellyin, F. and Wolodko, J.D. (2003). Observation on Damage Development in Fiber Reinforced Polymer Laminates Under Cyclic Loading, Int. J. Fatigue, 25: 437-446.
