Analysis of elastic stability and structural response of face-centered cubic crystals subject to [110] loading

摘要

The elastic stability and structural response of face-centered cubic crystals subject to uniaxial [110] loading are investigated systematically based on lattice-statics analysis, molecular-dynamics (MD) simulations, and symmetry and bifurcation considerations. The onset of instability in isostress MD simulations is found to be associated with loss or diminution of energy convexity (Born's stability criterion) as determined from computed strain and temperature dependent elastic moduli. Atomic mechanisms of crystal destabilization beyond the onset of instability are consistent with theoretical eigendeformations and are precursors to interatomic slip, which, in turn, may lead to failure or mechanical stacking faults.