This
paper presents the temperature dependence of in-plane thermal diffusivity and
anisotropy distribution for pitch-based carbon-fiber-reinforced polymers
(CFRPs). The measurement was performed using the laser-spot periodic heating
method. The samples were unidirectional (UD) and crossply (CP) CFRPs. All
carbon fibers of the UD samples ran in one direction, while those of the CP
samples ran in two directions. In both UD and CP CFRPs, from -80°;C to +80°;C, temperature
dependence of thermal diffusivity values increased as temperature decreased. In
this temperature range, the anisotropic ratio between the fiber direction and
its perpendicular direction of the UD CFRP was 106 - 124. During the anisotropy
distribution measurement, it was found that thermal anisotropy can be
visualized by scanning the laser in a circle on the sample. The thermal
diffusivity of the UD CFRP in the fiber direction was 17 times larger than that
in the 15°; direction, and the thermal diffusivity in the other directions was
lower than that in the 15°; direction. The anisotropy distribution for the CP
CFRP reflected its inhomogeneous structure.
References
[1]
Ohnishi, A. (2009) Mars-Observation Satellite “NOZOMI” and Asteroid-Observation Satellite “HAYABUSA”. Japan Journal of Thermophysical Properties, 23, 203-211.
[2]
Wrobel, G., Rdzawski, Z., Muzia, G. and Pawlak, S. (2009) Determination of Thermal Diffusivity of Carbon/Epoxy Composites with Different Fiber Content Using Transient Thermography. Journal of Achievements in Materials and Manufacturing Engineering, 37, 518-525.
[3]
Ellis, D.L. and McDanels, D.L. (1991) Thermal Conductivity and Thermal. Expansion of Graphite Fiber/Copper Matrix Composites. NASA Technical Memorandum 105233, NASA, Washington DC.
[4]
Mirmira, S.R., Renzi, D.F. and Fletcher, L.S. (1998) Transverse Thermal Conductivity and Contact Conductance of Fiber Reinforced Composite Materials. Proceedings of the 11th International Heat Transfer Conference, 7, 83-88.
[5]
Yamane, T., Katayama, S., Todoki, M. and Hatta, I. (1996) Thermal Diffusivity Measurement of Single Fibers by an AC Calorimetric Method. Journal of Applied Physics, 80, 4358-4365. http://dx.doi.org/10.1063/1.363394
[6]
Kalogiannakis, G., Van Hemelrijck, D., Longuemart, S., Ravi, J. and Okasha A. (2006) Thermal Characterization of Anisotropic Media in Photothermal Point, Line, and Grating Configuration. Journal of Applied Physics, 100, Article ID: 063521. http://dx.doi.org/10.1063/1.2335381
[7]
Carslaw, H.S. and Jaeger, J.C. (1959) Conduction of Heat in Solids. 2nd Edition, Chap.10, Oxford University Press, Oxford, 263.
[8]
Hatta, I., Fujii, K., Sakibara, A., Takahashi, F., Hamada Y. and Kaneda, Y. (1999) Two-Dimensional Effects on Measurement of Thermal Diffusivity by AC Calorimetric Method: I. Conditions for Precise Measurement. Japanese Journal of Applied Physics, 38, 2988-2992. http://dx.doi.org/10.1143/JJAP.38.2988
[9]
Gu, Y. and Hatta, I. (1991) Effect of Sample Edge in ac Calorimetric Method for Measuring Thermal Diffusivity of Thin Films with High Thermal Diffusivity. Japanese Journal of Applied Physics, 30, 1137-1138. http://dx.doi.org/10.1143/JJAP.30.1137
[10]
Nagano, H., Kato, H., Ohnishi, A. and Nagasaka, Y. (2001) Measurement of Thermal Diffusivity of Anisotropy Graphite Sheet using AC Calorimetric Method. International Journal of Thermophysics, 22, 301-312. http://dx.doi.org/10.1023/A:1006780208048
