  We present a discrete element method (DEM) model to simulate the mechanical
behavior of sea ice in response to ocean waves. The interaction of ocean waves
and sea ice can potentially lead to the fracture and fragmentation of sea ice
depending on the wave amplitude and period. The fracture behavior of sea ice is
explicitly modeled by a DEM method, where sea ice is modeled by densely packed
spherical particles with finite size. These particles are bonded together at
their contact points through mechanical bonds that can sustain both tensile and
compressive forces and moments. Fracturing can be naturally represented by the
sequential breaking of mechanical bonds. For a given amplitude and period of
incident ocean wave, the model provides information for the spatial
distribution and time evolution of stress and micro-fractures and the fragment
size distribution. We demonstrate that the fraction of broken bonds, ,
increases with increasing wave amplitude. In contrast, the ice fragment size l
decreases with increasing amplitude. This information is important for the
understanding of breakup of individual ice floes and floe fragment size.
