Page 360 - Engineered Interfaces in Fiber Reinforced Composites

Chapter 8. Improvement of interlaminar fracture toughness with interface control 34 1

'
500
a
-
5 400
F e
300- 0. *
.e
c *
in
3 200-
0 . e
-
(d e
g 100-
.-
v)
2

500
a
%OO-
5
w
300- 0 i
4- :*
in
3 200- 8e
-
0 e@
(d e@
3 100-
.-
u)
d
2
Fig. 8.10. Correlation of residual compression-after-impact (CAI) strength with composite mode I1
interlaminar fracture toughness, qiC. After Masters (l987a).

The improvement of damage resistance and tolerance in interlaminar fracture and
under impact loading for the toughened matrix composites is at the expense of other
important mechanical properties, such as inferior stiffness and hot/wet compressive
strength (Evans and Masters, 1987). These trade offs appear to be associated with
the reduction in matrix modulus and glass transition temperature (Jordan et al.,
1989).