Cracks patterns are in
uenced by the substrates beneath them. From buried craters to
crocodile skin, crack patterns are found over an enormous range of length scales. Regardless
of their scale, substrates can impart geometry and symmetry to a crack pattern. There are
two central problems discussed in this thesis - how does an uneven substrate a ect a crack
pattern? how can crack patterns be quanti ed? To answer these questions, crack patterns
are generated by drying mud slurries over sinusoidal and radially sinusoidal substrates. It is
observed that as the thickness of the cracking layer increases, the crack patterns transition
from wavy to ladder-like to isotropic. Four main measures of the crack pattern are introduced
to quantify the observations - one parameter which measures the relative alignment
of these crack networks, one parameter that measures the orientation of cracked regions, one
parameter which measures uses the Manhattan metric to compare crack patterns and Fourier
methods which are used to characterise the transitions between crack pattern types. These
results are explained these results with a model, based on the Gri th criteria of fracture.
This model suggests that there is a transition region between wavy to ladder-like cracks. The
metrics developed here and results can be adapted to any connected networks of crack
