Page 160 - Engineered Interfaces in Fiber Reinforced Composites

142 Engineered interfaces in jiber reinforced composites

m t
n 3
n
(3'2

1

n
"0 10 20 30 40 50 60
(b) L (mm)

Fig. 4.28. Comparisons between experiments and theory of (a) maximum debond stress, CJ:, and (b) initial
frictional pull-out stress for Sic fiber-glass matrix composites: (0) untreated fibers; (0) acid treated
fibers. After Kim et al. (1992).

(4.115)

Based on Lame's solution, the relationship between the IFSSs is taken as

q(b,z) =-Ti(.,.) by2 , (4.116)
UYl
where y2 = a2/(B2 - a2). The additional radial stress, q2(arz), acting at the fiber-
matrix interface, which is caused by Poisson contraction of the fiber when subjected