Composite Materials Research Progress

30
, , [MPa]
, , [MPa]
σ 11
150
100
50
-50
-100
-150
-200
-250
50
0
-50
-100
-150
-200
-250
200
0
0
a)
Jacquemin Frédéric and Fréour Sylvain
0,5 1 1,5 2 2,5 3 6 perm
0,5 1 1,5 2 2,5 3 6 perm
b)
month
month
, , [MPa]
, , [MPa]
150
100
50
0
-50
-100
-150
-200
0
-5
-10
-15
-20
-25
-30
-35
-40
AS4 50_1_1 ΔC m / ΔC I = 2
1 2 3 4 5 6 7 8
-200
-400
cas
0,5 1 1,5 2 2,5 3 6 perm
a)
month
0,5 1 1,5 2 2,5 3 6 perm
b)
month
composite (CMF) matrix (numerical) fiber (numerical)
matrix (analytical) fiber (analytical)
Figure 4. Local stresses in T300/5208 composite for the inner ply, in the case of a) the uni-directionaly
reinforced composite and b) the [+55°/-55°] S symmetric laminate. CMF stands for Continuum
Mechanics Formalisms.
This work demonstrates the complementarities of continuum mechanics and micromechanical
models for the prediction of a possible damage in composite structures submitted
to hygro-elastic loads.
In the following section, the analytical expressions presented here for the localization of
the macroscopic mechanical states within the plies constituents, will be inversed in order to
achieve the identification of the strength of the constitutive matrix of a composite ply.
5. Identification of the Local Strength of the Constitutive Matrix
of a Composite Ply
5.1. Introduction
Damage predictions are important for design and for guiding materials improvement for
engineering applications. Composite structures encountered in engineering applications