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SiC is an attractive material
for many technologies that require high performance in
extreme environments
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However, its utilization is often limited by a susceptibility to fracture
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Peridynamic approach enables a natural coupling of continuum mechanics modeling with atomistic simulation
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Hybrid Peridigm/ReaxFF modeling can be used to analyze crack formation at multiple scales
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Peridigm geometry - bar with dimensions of 2 x 0.2 x 0.002 µm
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LAMMPS geometry - slab with dimensions of 200 x 200 x 20 Å
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An elastic correspondence model with a Verlet integration scheme was used in Peridig
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LAMMPS simulation was performed for 3C-SiC crystal using ab-initio based ReaxFF

ReaxFF
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Both HHM and LAMMPS started from the same initial configuration of a 3C-SiC slab with pre-crack
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Prescribed compression created a rough fracture surface, disordering atomic packing within a few atomic planes
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HHM predicted a linear crack propagation along shear stress direction that is ~45 degrees relative to the direction of tension
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LAMMPS yielded crack branching with an angle greater than 90 degrees, whereas experiments (Ramulu et al, 1985) showed smaller branching angles
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Disagreement is likely because HHM and LAMMPS account differently for reflections of waves from the boundaries, which control crack branching
