Search for content and authors |
Ab Initio Calculations of the Critical Values of Elastic Energy Density |
Kinga T. Nalepka 2, Pawel Nalepka 1, Ryszard B. Pecherski 1,2 |
1. Polish Academy of Sciences, Institute of Fundamental Technological Research (IPPT PAN), Świętokrzyska 21, Warszawa 00-049, Poland |
Abstract |
An energy-based approach to limit states in elastic solids of arbitrary anisotropy was developed by Rychlewski [1]. It is based on the theory of elastic eigen-states and the concept of energy orthogonal stress states, which make it possible to decompose additively the elastic energy density into not more than six disjoint parts. Such an approach can appear also helpful in the field of nanomechanics filling the gap between atomistic calculations and continuum mechanics modelling of the behaviour of different kinds of crystalline nanostructures and macroscopic material properties. Under the limit state in nanostructures, we can understand the limit of linear elastic behaviour. We propose to calculate the critical energy of pertinent elastic eigen-states from quantum mechanical theory of nc-metals [2]. The analysis is confined to the cubic crystals. In such a case, three elastic eigen-states exist. The quantum mechanical model for an ideal single crystal of Cu is studied and the comparison with the results obtained for Al crystal is made. Using the Wigner-Seitz cellular approach and the Slater method the structure of the s, d, f and p energy bands was calculated. This enables obtaining of the internal energy of the crystal volume confined in the deforming Wigner-Seitz cell. Finally the critical energy for the particular elastic eigen-state was determined.
|
Legal notice |
|
Presentation: oral at E-MRS Fall Meeting 2004, Symposium H, by Ryszard B. PecherskiSee On-line Journal of E-MRS Fall Meeting 2004 Submitted: 2004-05-17 09:12 Revised: 2009-06-08 12:55 |