C. Beldica et J. Botsis, EXPERIMENTAL AND NUMERICAL-STUDIES IN MODEL COMPOSITES .2. NUMERICAL RESULTS, International journal of fracture, 82(2), 1996, pp. 175-192
A numerical approach using the boundary element method for strength an
d toughness of a composite with long aligned fibers is reported. The t
hree-dimensional problem is reduced to a two-dimensional one by substi
tuting the rows of fibers with layers of appropriate width and elastic
constants. The configuration examined in this work is a compact tensi
on specimen similar to that used in the experimental studies (Part I,
[1]). The experimental results on strength and apparent fracture tough
ness are compared with the numerical results. For the particular geome
try and fiber spacing, the numerical simulations are in good agreement
with the experimental findings, i.e. the composite's strength sigma(A
), scales with the fiber spacing lambda, in the form of sigma(A)=kappa
/root lambda. Using the numerical formalism a number of different geom
etries was examined. The simulations suggested that if the external sp
ecimen characteristics remain the same and the fiber spacing in the di
rection of crack advance is changed, then the strength of the composit
e specimen can be expressed sigma(A)=sigma(Ao)+kappa/root lambda(x). I
f the fiber spacing varies in both directions simultaneously, for a ce
rtain range of lambda, it can be considered that the composite's stren
gth sigma(A), is proportional to 1/root lambda.