Composite Materials Research Progress

40
&22 [MPa]
& & [MPa]
& & [MPa]
-4000 -3000 -2000 -1000-50 0 1000 2000
T300/5208
N5208
Jacquemin Frédéric and Fréour Sylvain
50
-150
-250
-350
& 11 [MPa]
-500 -400 -300 -200 -100 0 100
-100
T300/5208
N5208
100
50
-250 -200 -150 -100 -50 0 50
T300/5208
N5208
σ 22 [MPa]
& 22 [MPa]
200
100
0
-200
-300
-400
-500
0
-50
-100
& & &[MPa]
σ 33 [MPa]
& & [MPa]
-4000 -3000 -2000 -1000-50 0 1000 2000
AS4/3501
3501-6
50
-150
-250
-350
σ 11 [MPa]
200
-500 -400 -300 -200 -100 0 100
AS4/3501
3501-6
σ 22 [MPa]
0
-200
-400
100
50
-250 -200 -150 -100 -50 0 50
AS4/3501
3501-6
σ 22 [MPa]
Figure 5. Examples of macroscopic and local (matrix only) stress failure envelopes of T300/5208 and
AS4/3501-6 plies.
5.3.2. Observations on Predicted Results and Discussion
According to the identification procedure described in subsection 5.2.3, an infinite number of
I I I I
macroscopic stress states sets { σ a , σ b , σ c , σ d } can be considered for the determination
I
of the researched microscopic failure envelope strength coefficients. Actually, σ c only may
I
a
I
b
I
d
vary whereas σ , σ and σ are fixed by the macroscopic ultimate stresses
of the considered composite structure (see the first raw of Table 7). Several tests were
0
-50
-100
I
Y ,
/
I
Y ,
I
S