Dislocation dynamics simulations were used to investigate the acoustic nonlinearity created by dislocations in crystals. The acoustic non-linearity parameter, β, was quantitatively predicted for a single dislocation bowing in its glide plane between pinning points under a quasistatic loading assumption using dislocation dynamics simulations. The existing model using a constant line energy assumption fails to capture the correct behaviour of β for edge dislocations in materials with a nonzero Poisson’s ratio. A strong dependence of β on the orientation of Burgers vector relative to the line direction of the dislocation was shown by the dislocation dynamics simulations. A new model using an orientation-dependent line energy was derived for the cases of initially pure edge and screw dislocations. The model was shown to agree with the dislocation dynamics simulations over a range of Poisson’s ratio and static stresses.

Dislocation Contribution to Acoustic Nonlinearity: the Effect of Orientation-Dependent Line Energy. W.D.Cash, W.Cai: Journal of Applied Physics, 2011, 109[1], 014915