Composite Materials Research Progress

T300 fibers
(Soden et al.,
1998;
Agbossou and
Pastor, 1997)
N5208 epoxy
matrix (Tsai,
1987;
Agbossou and
Pastor, 1997)
Multi-scale Analysis of Fiber-Reinforced Composite Parts… 11
Table 1. Hygro-thermo-mechanical properties of T300/5208 constituents.
ρ
[g/cm 3 ]
Y 1
[GPa]
Y 2, Y3
[GPa]
ν12
ν
13
G23
[GPa]
G 12
[GPa]
M11
[10 -6 /K]
M22, M 33
[10 -6 /K]
11 22 β , β
1200 230 15 0.2 7 15 -1.5 27 0
1867 4.5 4.5 0.4 6.4 6.4 60 60 0.6
The calculations were achieved assuming that the reinforcements exhibit fiber-like
morphology with an infinite length axis parallel to the longitudinal direction of the ply. For
the determination of the CME, a perfect adhesion between the carbon fibers and the resin was
assumed. Moreover, it also was assumed that the fibers do not absorb any moisture. Thus, the
ratio between the pseudo-macroscopic and the macroscopic moisture contents is deduced
from the expression given in (Loos and Springer, 1981):
m
I
I
ρ
m m
ΔC
= (16)
ΔC v ρ
where ρ stands for the densities. The macroscopic density can be deduced form the classical
rule of mixture:
I m m r r
= v ρ v ρ
(17)
ρ +
The equations required for achieving Mori-Tanaka estimations involve relations (8-17).
For the purpose of the strain localization, the embedding constituent was considered to be the
epoxy matrix, whatever the considered volume fraction of reinforcements (thus, the
e m
transformation rule L = L was considered to be valid in any case). Figure 1 also reports
the numerical results obtained through Kröner-Eshelby Self-Consistent model (1-3, 6-10, 16-
17), in the same conditions (identical inclusion morphology and constituents properties as for
Mori-Tanaka computations).
β
33