Hostname: page-component-84b7d79bbc-g5fl4 Total loading time: 0 Render date: 2024-07-25T21:17:49.205Z Has data issue: false hasContentIssue false

Non-Local Elasticity Kernels Extracted from Atomistic Simulations

Published online by Cambridge University Press:  01 February 2011

Get access

Abstract

Non-local elasticity kernels are calibrated based on the atomic scale structure of glasses obtained from atomistic simulations. A model Morse material, with interatomic interactions described by a pair potential, and Al, characterized by an embedded-atom potential are considered. The study is limited to linear isotropic non-local elasticity. The functional form of the derived kernels is significantly different than that usually assumed in non-local constitutive models (Gaussian). They have a range that extends up to the cut-off radius of the interatomic potential, are positive at the origin, and become negative approximately one atomic distance away. These kernels involve 2 internal length scales that are both derived from atomistics for the materials mentioned above. The kernel for Al is tensorial, a different function weighting each entry of the stiffness tensor. Model materials interacting by pair potentials may be described by a single function that weights the whole stiffness tensor. Two applications are briefly described in closure. The new non-local model improves upon the Gaussian one by predicting a more realistic wave dispersion relationship, with essentially zero group velocity at the boundary of the Brillouin zone. Next, the role of non-locality in defining the Peierls stress of a dislocation is studied within a Peierls-Nabarro model and it is shown that the predictions of the critical stress improve upon consideration of non-locality.

Type
Research Article
Copyright
Copyright © Materials Research Society 2002

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

1 Eringen, A.C., Edelen, D.G.B., Int. J. Eng. Sci. 10, 233 (1972).Google Scholar
2 Kunin, I.A., Elastic media with microstructure, Springer, New York (1982).Google Scholar
3 Valanis, K.C., Arch. Mech. 52, 817 (2000).Google Scholar
4 Altan, S.B., Aifantis, E.C., Scripta Met. Mater. 26, 319 (1992).Google Scholar
5 Gutkin, M.Y., Aifantis, E.C., Scripta Mat. 40, 559 (1999).Google Scholar
6 Aifantis, E.C., J. Eng. Mat. Technol. 121, 189 (1999).Google Scholar
7 Eringen, A.C., J. Appl. Phys. 54, 4703 (1983).Google Scholar
8 Eringen, A.C., Res Mech. 21, 313 (1987).Google Scholar
9 Picu, R.C., “On the functional form of non-local elasticity kernels,” J. Mech. Phys. Sol., to appear (2002).Google Scholar
10 Picu, R.C., J. Mech. Phys. Sol. 50, 717 (2002).Google Scholar
11 Kittel, C., Introduction to solid state physics, John Wiley, New York (1956).Google Scholar