  Using a discrete-element approach and a bonding interaction law, we model and
test crushable inherently anisotropic structures reminiscent of the layering
found in sedimentary and metamorphic rocks. By systematically modifying the
level of inherent anisotropy, we characterize the evolution of the failure
strength of circular rock samples discretized using a modified Voronoi
tesselation under diametral point loading at different orientations relative to
the sample's layers. We characterize the failure strength, which can
dramatically increase as the loading becomes orthogonal to the rock layers. We
also describe the evolution of the macroscopic failure modes as a function of
the loading orientation and the energy consumption at fissuring. Our simulation
strategy let us conclude that the length of bonds between Voronoi cells
controls the energy being consumed in fissuring the rock sample, although
failure modes and strength are considerably changing. We end up this work
showing that the microstructure is largely afected by the level of inherent
anisotropy and loading orientation.
