volume | PIER Journals

Abstract

This paper explores the effects of extended exposure to salt water fog on the microwave absorption properties of unidirectional carbon-fiber reinforced polymer (CFRP) circuit analog absorbers (CAA). Single-layer CFRP CAAs were fabricated using a wet-layup technique and were then subjected to a controlled salt water fog chamber following B117 standards. A total of ten samples using 305 g/m² areal-weight unidirectional CFRP were fabricated. Three samples were withdrawn from the salt water environment at ten-day intervals and tested, with the final samples being withdrawn after 30 days. The mass of each sample was measured immediately after removal to measure mass-accumulation and after a five-day interval to measure mass-loss. A free-space microwave reflection measurement system was implemented to track and quantify changes to the absorption capabilities of the CAA. A physically-based electromagnetic model was developed to characterize the changes caused by salt water absorption, and good agreement was observed with measured data.

1. Mangalgiri, P. D., "Composite materials for aerospace applications," Bull. Mater. Sci., Vol. 22, No. 3, 657-664, 1999.
doi:10.1007/BF02749982

2. Mouritz, A. P., E. Gellert, P. Burchill, and K. Challis, "Review of advanced composite structures for naval ships and submarines," Compos. Struct., Vol. 53, No. 1, 21-22, 2001.
doi:10.1016/S0263-8223(00)00175-6

3. Shen, C. H. and G. S. Springer, "Moisture absorption and desorption of composite materials," J. Compos. Mater., Vol. 10, No. 1, 2-20, 1976.
doi:10.1177/002199837601000101

4. Springer, G. S., "Environmental effects on epoxy matrix composites," Composite Materials: Testing and Design (Fifth Conference), 291-312, Tsai S. W. (ed), Philadelphia, PA, 1979.

5. Shirrell, C. D. and J. Halpin, "Moisture absorption and desorption in epoxy composite laminates," Composite Materials: Testing and Design (Fourth Conference), 514-528, Davis Jr., J. G. (ed), Philadelphia, PA, 1977.

6. Selzer, R. and K. Friedrich, "Mechanical properties and failure behaviour of carbon fibre-reinforced polymer composites under the influence of moisture," Compos. Part A, Vol. 28, No. 6, 595-604, 1997.
doi:10.1016/S1359-835X(96)00154-6

7. Almudaihesh, F., K. Holford, R. Pullin, and M. Eaton, "The influence of water absorption on unidirectional and 2D woven CFRP composites and their mechanical performance," Compos. Part B, Vol. 182, 107626, 2020.
doi:10.1016/j.compositesb.2019.107626

8. Jafar, H. I., S. I. Husaen, and E. A. Al-Ajaj, "Effect of water absorption on some electrical and dielectrical properties of epoxy resin reinforced with chopped carbon fibers," Al-Nahrain J. Sci., Vol. 14, 87-94, 2011.

9. Gadja, W. J., Measurement of the electrical properties of composite materials in the frequency range of DC to 30 MHz, Report RADC-TR-79-03, Syracuse University, USA, August 1979.

10. Munk, B., Frequency Selective Surfaces: Theory and Design, Wiley, 2000.
doi:10.1002/0471723770

11. Fante, R. L. and M. T. McCormack, "Reflection properties of the Salisbury screen," IEEE Trans. Antennas Propag., Vol. 36, No. 10, 1443-1454, 1988.
doi:10.1109/8.8632

12. O'Donnell, J. C. and R. M. Narayanan, "Impact damage characterization for varying areal-weight unidirectional carbon fiber-reinforced polymer circuit-analog absorbers," Compos. Part B, Vol. 202, 108427, 2020.
doi:10.1016/j.compositesb.2020.108427

13. O'Donnell, J. C., R. M. Narayanan, and E. H. Lenzing, "Analysis of damage in unidirectional CFRP circuit analog absorbers," IEEE National Aerospace and Electronics Conference (NAECON 2018), 555-560, Dayton, OH, USA, IEEE, Piscataway, July 23–26, 2018.

14. O'Donnell, J. C., E. J. Riley, and R. M. Narayanan, "Electromagnetic response changes of unidirectional carbon fiber-reinforced polymer circuit-analog absorbers due to post-processing impact damage," SPIE Conference on Radar Sensor Technology XXIII, Baltimore, MD, USA, SPIE, Bellingham, WA, April 14–18, 2019.

15. Riley, E. J., E. H. Lenzing, and R. M. Narayanan, "Application of unidirectional carbon-fiber-reinforced-polymer laminas in circuit-analog absorbers," IEEE Trans. Electromagn. Compat., Vol. 60, No. 6, 1743-1751, 2018.
doi:10.1109/TEMC.2017.2781142

16. Zafar, A., F. Bertocco, J. Schjødt-Thomsen, and J. C. Rauhe, "Investigation of the long term effects of moisture on carbon fibre and epoxy matrix composites," Compos. Sci. and Tech., Vol. 72, No. 6, 656-666, 2012.
doi:10.1016/j.compscitech.2012.01.010

17. Gao, C. and C. Zhou, "Moisture absorption and cyclic absorption-desorption characters of fibre-reinforced epoxy composites," J. Mater. Sci., Vol. 54, 8289-8301, 2019.
doi:10.1007/s10853-019-03399-7

18. Kafodya, I., G. Xian, and H. Li, "Durability study of pultruded CFRP plates immersed in water and seawater under sustained bending: Water uptake and effects on the mechanical properties," Compos. Part B, Vol. 70, 138-148, 2015.
doi:10.1016/j.compositesb.2014.10.034

19. Grace, L. R., "The effect of moisture contamination on the relative permittivity of polymeric composite radar-protecting structures at X-band," Compos. Struc., Vol. 128, 305-312, 2015.
doi:10.1016/j.compstruct.2015.03.070

20. Fink, B. K., R. L. McCullough, and J. W. Gillespie, "The influence of moisture on dielectric behavior of poly-etheretherketone/carbon fiber composites," J. Thermoplast. Compos. Mater., Vol. 5, No. 2, 90-104, 1992.
doi:10.1177/089270579200500201

21. Reid, J. D., W. H. Lawrence, and R. P. Buck, "Dielectric properties of an epoxy resin and its composite I. Moisture effects on dipole relaxation," J. Appl. Polym. Sci., Vol. 31, 1771-1784, 1986.
doi:10.1002/app.1986.070310622

22. Diab Group, Divinycell H datasheet, , www.diabgroup.com/en-GB/Products-and-services/Core-Material/Divinycell-H (2020, accessed 5 March 2020).

23. Im, K.-H., et al., "Influence of terahertz waves on unidirectional carbon fibers in CFRP composite materials," Mater. Sci. (Medziagotyra), Vol. 20, No. 4, 457-463, 2014.

24. Riley, E. J., E. H. Lenzing, and R. M. Narayanan, "X-band circuit-analog absorbers using unidirectional carbon-fiber laminas," IEEE Antennas Wirel. Propag. Lett., Vol. 17, No. 6, 1060-1063, 2018.
doi:10.1109/LAWP.2018.2831909

25. Morey, R. M., A. Kovacs, and G. F. N. Cox, "Electromagnetic properties of sea ice," Cold Regions Science and Technology, Vol. 9, No. 1, 53-75, 1984.
doi:10.1016/0165-232X(84)90048-X

26. Stogryn, A. and G. J. Desargant, "The dielectric properties of brine in sea ice at microwave frequencies," IEEE Trans. Antenna and Propag., Vol. 33, No. 5, 523-532, 1985.
doi:10.1109/TAP.1985.1143610

27. Khalil, H. P. S. A., M. Jawaid, and A. A. Bakar, "Woven hybrid composites: Water absorption and swelling behaviours," BioResour., Vol. 6, No. 2, 1043-1052, 2011.

28. Mariatti, M., M. Jannah, A. A. Bakar, and H. P. S. A. Khalil, "Properties of banana and pandanus woven fabric reinforced unsaturated polyester composites," J. Compos. Mater., Vol. 42, No. 9, 931-941, 2008.
doi:10.1177/0021998308090452

Dr. Joseph C. O'Donnell

Prof. Ram M. Narayanan