A homogenized analytic model for average moisture uptake in composite laminates containing periodically distributed matrix-cracks is presented. It is shown that the model, compared to FE-calculations, well decribes moisture absorption in a cross-ply composite laminate containing periodically distributed transverse matrix cracks in the 90° plies. The homogenized model is based on a two-phase model consisting of the crack channels and the composite material respectively. An analytic solution to the two-phase model for moisture uptake in composite laminates is presented. The model can be used to judge whether micro cracks are of importance or not concerning moisture absorption.
1. Jost, W.1952. Diffusion in Solids, Liquids, Gases. New York: Academic Press.
2.
2. Crank, J.1975. The mathematical theory of diffusion, 2. ed., Oxford: Oxford University Press.
3.
3. Shen, C. H. and Springer, G. S.1976. "Moisture Absorption and Desorption of Composite Materials,"J. Comp. Mater., 10:2-20.
4.
4. Browning C. E., Husman, G. E., and Whitney, J. M. 1977. "Moisture effects in epoxy matrix composites." in Composite Materials: Testing and Design (Fourth Conference) ASTM STP 617, Philadelphia. PA: American Society for Testing and Materials, pp. 481-496.
5.
5. Springer G. S. 1979. "Environmental effects on epoxy matrix composites," in Composite Materials: Testing and Design (fifth conference) ASTM STP 674, S. W. Tsai, ed., Philadelphia, PA: American Society for Testing and Materials, pp. 291-312.
6.
6. Wong, T. C. and Broutman, L. J.1985. "Moisture diffusion in epoxy resins part 1. Non-Fickian sorption processes,"Polym. Eng. Sci., 25:521-528.
7.
7. Jackson, S. P. and Weitsman, Y. 1985. "Moisture effects and moisture induced damage in composites," in Fifth International Conference on Composite Materials ICCM-V, W. C. Harrigan, ed., Warrendale, Metallurgical Society, pp. 1435-1452.
8.
8. Wu, J. C. and Peppas, N. A.1993. "Modeling of penetrant diffusion in glassy polymers with an integral sorption deborah number,"J. Polym. Sci., Polym. Phys., 31:1503-1518.
9.
9. Cai, L.-W. and Weitsman, Y.1994. "Non-Fickian moisture diffusion in polymeric composites,"J. Comp. Mater., 28:130-154.
10.
10. Adolfsson, E. and Gudmundson, P.1997. "Thermoelastic properties in combined bending and extension of thin composite laminates with transverse matrix cracks,"Int. J. Solids Structures, 34:2035-2060.
11.
11. Highsmith, A. L., Stinchcomb, W. W. and Reifsnider, K. L.1984. "Effect of fatigue-induced defects on the residual response of composite laminates," in Effects of Defects in Composite Materials, ASTM STP 836, Philadelphia, PA: American Society for Testing and Materials, pp. 194-216.
12.
12. Landolt-Börnstein 1969. Zahlenwerte und funktionen, 6 auflage, 5 teil, bandteil a. Transport-phänomene I, K. Schäfer, ed., Springer Verlag.
13.
13. Loos, A. C. and Springer, G. S.1981. "Environmental effects on composite materials," in Environmental Effects on Composite Materials, G. S. Springer, ed., Westport, CT: Technomic Publishing Company, Inc., pp. 34-50.
14.
14. Weitsman, Y.1987, "Coupled damage and moisture-transport in fiber-reinforced, polymeric composites,"Int. J. Solids Structures, 23:1003-1025.
15.
15. Carter, H. G. and Kibler, K. G.1978. "Langmuir-type model for anomalous moisture diffusion in composite resins,"J. Comp. Mater., 12, 118-131.
16.
16. Gurtin, M. E.och Yatomi, C.1979. "On a model for two phase diffusion in composite materials,"J. Comp. Mater., 13, 126-130.
17.
17. Carslaw, H. S. and Jaeger, J. C.1959. Conduction of heat in solids, 2. ed., Oxford, Great Britain: University Press, pp. 144-146.
18.
18. ABAQUS User's Manual Version 5.51995. Pawtucket, Rhode Island: Hibbit, Karlsson & Sorensen, Inc.
