Influence of inertia on the formation of dislocation dipoles
Résumé
The stability of an edge dislocation dipole is analysed with two different simulation techniques. The first one utilizes the Peierls-Nabarro Galerkin method, where the time-dependent displacement field around dislocations is computed with a finite-element code. The method, used as a reference, naturally accounts for inertial effects and reproduces unsteady dislocation motion with accompanying stress waves emission. The second technique uses a two-dimensional dislocation dynamics code which relies on expressions for relativistic effective dislocation masses and related analytic approximation of the interaction force. Comparison between the results obtained with the two techniques for various viscosities and driving forces show that, as far as dipole obstacles are concerned, inertial effects are important, but that relativistic effects may be neglected.