Page 324 - Engineered Interfaces in Fiber Reinforced Composites

Chapter 7. Improvement of transverse fracture toughness with interface control 305

1.4 i

0 0.2 0.4 0.6 0.8 1 1.2 1 4
(a) Young's modulus ratio, Ei /E ,,,

u)1 Oai
u)
E
- 0.8 Oci
Q .-
0
2 0.6
-
Q
4 0.4
.-
u)
3 0.2
0~""""""'
0 0.2 0.4 0.6 0.8 1 1.2 1.4

(b) Young's modulus ratio, Ei /E ,,,
Fig. 7.15. Normalized residual radial stress as a function of Young's modulus ratio, Ei/E,, for varying
coating thickness, t/u = 0.05, 0.1, 0.2. Coefficients of thermal expansion (CTE) of the coating: (a)
2, = 100 x IO-('/"C; (b) 4 = 20 x 10-6rC. After Kim and Mai (1996a, b).

Table 7.3
Mechanical properties of carbon fiber-epoxy matrix compositesa.

Carbon-epox y 230 0.2 3.0 0.4 37.7 1.25 -9.97

aAfter Kim et al. (1992).