25000
-*-Anisotropic Solutions for <10-1>
20000 .- Isotropic Solution for <10-1>
20000 --
SAnisotropic Solutions for <-12-1>
*- Isotropic Solutions for <-12-1>
'5 15000
10000
-................
0
0 --------------------------------------
0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9
Crack Length / Diameter ratio
Figure 5-7: K, versus Crack Length/Diameter ratio for [10] and [121] orientation
of Specimen 'B' at Q 00.
the magnitude of Kn1 for the [121] orientation is greater than that for the [101]
orientation, it may not affect the effective SIF very much, as the magnitude of K111
for the [101] orientation is far greater than that for the [121] orientation.
The values of K, for the [101] orientation rapidly decrease as compared to
the [121] orientation and reach crack closure angle at around 180, whereas the
crack closure angle is 300 for the [172] orientation. The magnitude of K/i for
[121] is alv--, greater than that for the [101] orientation, but the difference is far
less in comparison to the magnitude of K111 for the [121] and [t10] orientations.
Following the work of Sauma and Sikiotis [31], the calculated values for Knli were
found to be negligible and after much analysis and rederiving of relevant equations,
the equation given by Sauma and Sikiotis was found to be wrongly formulated. On
the other hand, equation (3.5) correctly gave rise to all the three modes of SIFs. As
a result of the coupling of displacements at the crack tip due to anisotropy, non-
negligible values of K111 were found, and they varied with respect to the applied
force, crack length and crack angle.