Figure 6: Void
(a,b ) dip \(\phi\) and (c,d ) strike \(\theta\)probability distributions at each strain increment for (a,c )
the untreated sample and (b,d ) the heat-treated sample,
calculated using the object-based best-fitting ellipsoid approach. Inset
shows the measured angles with respect to the principal stress axes:\(\phi=90\) is parallel to the \(z\)-axis, while \(\theta=0\) is
parallel with the \(y\)-axis. Labels on the dip distributions show the
angles at which different damage mechanisms are prevalent. Strike
distributions are normalized to the minimum \(P\left(\theta\right)\)of the starting porosity. Blue distributions overlaying the rest are
post-failure.