Comment on ``Mechanical analog of temperature for the description of force distribution in static granular packings''
Abstract
It has been proposed by Ngan [Phys. Rev. E 68, 011301 (2003)] that the granular contact force distribution may be analytically derived by minimizing the analog of a thermodynamic free energy, in this case consisting of the total potential energy stored in the compressed contacts minus a particular form of entropy weighted by a parameter. The parameter is identified as a mechanical temperature. I argue that the particular form of entropy cannot be correct and as a result the proposed method produces increasingly errant results for increasing grain rigidity. This trend is evidenced in Ngan’s published results and in other numerical simulations and experiments.
- Publication:
-
Physical Review E
- Pub Date:
- May 2004
- DOI:
- 10.1103/PhysRevE.69.053301
- arXiv:
- arXiv:cond-mat/0403040
- Bibcode:
- 2004PhRvE..69e3301M
- Keywords:
-
- 45.05.+x;
- 45.70.-n;
- 81.05.Rm;
- 05.70.-a;
- General theory of classical mechanics of discrete systems;
- Granular systems;
- Porous materials;
- granular materials;
- Thermodynamics;
- Condensed Matter - Statistical Mechanics
- E-Print:
- 4 pages, 1 figure, minor editorial corrections