Speaker
Nicolas Van Goethem
(Universidade de Lisboa)
Description
We propose a mechanism for the onset of polygonization in crystals with dislocations. Starting from a diffuse distribution, we show that the interaction between elasticity and dislocation motion can destabilize the homogeneous state. The classical Peach–Koehler force tends to stabilize this state, while a non-local Beltrami contribution drives the instability.
The fastest-growing structures are oriented at 45^\circ, although no characteristic spacing is selected at this stage. Two numerical simulations illustrate the formation of these patterns and their possible evolution toward polygonized dislocation walls under bending.
Author
Nicolas Van Goethem
(Universidade de Lisboa)