Dislocation drag and its influence on elastic precursor decay

Plastic deformation is mediated by the creation and movement of dislocations, and at high stress the latter is dominated by dislocation drag from phonon wind. By simulating a 1-D shock impact problem we analyze the importance of accurately modeling dislocation drag and dislocation density evolution in the high stress regime. Dislocation drag is modeled according to a first principles derivation as a function of stress and dislocation character, and its temperature and density dependence are approximated to the extent currently known. Much less is known about dislocation density evolution, leading to far greater uncertainty in these model parameters. In studying anisotropic fcc metals with character dependent dislocations, the present work generalizes similar earlier studies by other authors.

Automated summary

The translation mainly discusses the influence of dislocations on plastic deformation and the importance of accurately modeling dislocation drag and dislocation density evolution under high stress conditions. On one hand, dislocation drag is modeled based on first principles derivation, with its dependence on stress and dislocation character; on the other hand, much less is known about dislocation density evolution, leading to greater uncertainty in model parameters.