Session P33: Focus Session: Friction, Fracture and Deformation III

11:15 AM–1:39 PM, Wednesday, March 15, 2006
Baltimore Convention Center Room: 336

Sponsoring Units: DMP GSNP
Chair: Yue Qi, General Motors Research and Development

Abstract ID: BAPS.2006.MAR.P33.1

Abstract: P33.00001 : Atomistic Simulation of Size Effects in Bending a Single Crystal

11:15 AM–11:27 AM

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Authors:

  N. Scott Weingarten
    (The Catholic University of America)

  Robin Selinger
    (Kent State University)

We perform atomistic Monte Carlo simulations of bending a Lennard-Jones single crystal in two dimensions. In examining initial yield, we find an apparent ``reverse'' size effect. However, when strain rate effects are taken into account, we demonstrate that the size effect disappears. Once geometrically necessary dislocations coalesce to form grain boundaries, we observe a size effect of the usual kind, e.g. smaller samples support a higher scaled bending moment than larger samples. We compare simulation results with recent experiments on bending of highly annealed nanowires [B. Wu et al, Nature Matls 4, 525, 2005.] Finally, we observe a topological instability in the evolution of a grain boundary intersecting a free surface under compressive stress. The grain boundary buckles and nucleates a protruding grain, suggesting a novel mechanism for the formation of a hillock on a compressed metal surface.

To cite this abstract, use the following reference: http://meetings.aps.org/link/BAPS.2006.MAR.P33.1