Advanced Composite Materials

The Korean Society for Composite Materials (한국복합재료학회)
권호 표지
DOI QR코드

DOI QR Code

Analysis of Time-Dependent Deformation of CFRP Considering the Anisotropy of Moisture Diffusion

  • Arao, Yoshihiko (Graduate School of Waseda University) ;
  • Koyanagi, Jun (Japan Aerospace Exploration Agency, Institute of Space and Astronautical Science) ;
  • Hatta, Hiroshi (Japan Aerospace Exploration Agency, Institute of Space and Astronautical Science) ;
  • Kawada, Hiroyuki (Department of Mechanical Engineering, Waseda University)
  • Published : 2008.12.01
Download PDF
⟨ Previous Next ⟩

Abstract

The moisture absorption behavior of carbon fiber-reinforced plastic (CFRP) and its effect on dimensional stability were examined. Moisture diffusivity in CFRP was determined by measuring a specimen's weight during the moisture absorption test. Three types of CFRP specimens were prepared: a unidirectionally reinforced laminate, a quasi-isotropic laminate and woven fabric. Each CFRP was processed into two geometries - a thin plate for determination of diffusivity and a rod with a square cross-section for the discussion of two-dimensional diffusion behavior. By solving Fick's law expanded to 3 dimensions, the diffusivities in the three orthogonal directions were obtained and analyzed in terms of the anisotropy of CFRP moisture diffusion. Coefficients of moisture expansion (CMEs) were also obtained from specimen deformation caused by moisture absorption. During moisture absorption, the specimen surfaces showed larger deformation near the edges due to the distribution of moisture contents. This deformation was reasonably predicted by the finite element analysis using experimentally determined diffusivities and CMEs. For unidirectional CFRP, the effect of the fiber alignment on CME was analyzed by micromechanical finite element analysis (FEA) and discussed.

Keywords

References

  1. A. Kelly, R. J. Stearn and L. N. McCartney, Composite materials of controlled thermal expansion, Compos. Sci. Technol. 66, 154-159 (2006). https://doi.org/10.1016/j.compscitech.2005.04.025
  2. E. G. Wolff, Introduction to the Dimensional Stability of Composite Materials, DEStech Publications, Lancaster, PA (2004).
  3. T. Ozaki, K. Naito, I. Mikami and H. Yamauchi, High precision pipes for SORAR-B optical structures, Acta Astronautica 4, 85-120 (2001).
  4. C. H. Shen and G. S. Springer, Moisture absorption and desorption of composite materials, J. Compos. Mater. 10, 2-21 (1976). https://doi.org/10.1177/002199837601000101
  5. A. C. Loos and G. S. Springer, Moisture absorption of graphite/epoxy composites immersed in liquid and in humid air, J. Compos. Mater. 13, 131-147 (1979). https://doi.org/10.1177/002199837901300205
  6. A. Benkeddad, M. Grediac and A. Vautrin, Computation of transient hygroscopic stresses in laminated composite plates, Compos. Sci. Technol. 56, 869-876 (1996). https://doi.org/10.1016/0266-3538(96)00034-6
  7. A. Benkeddad, M. Grediac and A. Vautrin, On the transient hygroscopic stresses in laminated composite plates, Compos. Struct. 30, 201-215 (1995). https://doi.org/10.1016/0263-8223(94)00033-6
  8. A. Benkeddad, M. Grediac and A. Vautrin, On the transient hygroscopic stresses in laminated composite plates, Compos. Struct. 30, 201-215 (1995). https://doi.org/10.1016/0263-8223(94)00033-6
  9. A. Collings and D. E. W. Stone, Hygrothermal effects in CFRP laminates: strains induced by temperature and moisture, Composites 16, 307-316 (1985). https://doi.org/10.1016/0010-4361(85)90283-6
  10. R. A. Shapery, Thermal expansion coefficients of composite materials based on energy principles, J. Compos. Mater. 2, 380-404 (1968). https://doi.org/10.1177/002199836800200308
  11. H. S. Choi, K. J. Ahn and J. D. Nam, Hygroscopic aspects of epoxy/carbon fiber composite laminates on aircraft environment, Composites, Part A 32, 709-720 (2001). https://doi.org/10.1016/S1359-835X(00)00145-7
  12. D. F. Adam and F. Donald, Hygrothermal microstresses in unidirectional composite exhibiting inelastic material behaviour, J. Compos. Mater. 11, 285-299 (1977). https://doi.org/10.1177/002199837701100304