scholarly journals Coarse-grained free-energy-functional treatment of quasistatic multiscale processes in heterogeneous materials

2005 ◽  
Vol 123 (16) ◽  
pp. 164109 ◽  
Author(s):  
H. Zhou ◽  
R. Feng ◽  
D. J. Diestler ◽  
X. C. Zeng
1980 ◽  
Vol 33 (9) ◽  
pp. 2013 ◽  
Author(s):  
S Nordholm ◽  
ADJ Haymet

A generalized van der Waals theory is derived on the basis of simple physical and mathematical arguments. The derivation results in a free- energy functional wherein the independent variable is a coarse-grained particle density. It is assumed that a well defined particle density dominates the free energy and this density is to be obtained by minimizing the free energy functional. The variational theory so obtained can be applied to non-uniform fluids. In the present work the possibility of stable non-uniform structure is neglected and the theory is applied to uniform fluids. It then produces an equation of state identical in form to that proposed originally by van der Waals but the excluded volume is only about half as large in the three-dimensional case. Applications to several two- and three-dimensional systems indicate that the new equation of state is a distinct improvement over the traditional van der Waals theory when the full range of fluid densities is considered. The quantitative accuracy in the case of simple uniform fluids is sufficient to warrant further development and exploitation of the theory.


1999 ◽  
Vol 580 ◽  
Author(s):  
M. E. Gracheva ◽  
J. M. Rickman ◽  
J. D. Gunton ◽  
D. C. Coffey

AbstractResults are presented for the coarse grained distribution function and Ginzburg-Landau free energy function for coexistence of liquid and gas phases. These distribution functions were obtained by two different methods: 1) the compilation of particle density information from different coarse-grained cells using the canonical ensemble, and 2) the compilation of energy and density information from a single simulation cell by tuning the chemical potential using the grand-canonical ensemble. Both methods permit the calculation of a coarse-grained free energy functional which links the atomic and mesoscopic length scales.


Author(s):  
Olivier Ozenda ◽  
Epifanio G. Virga

AbstractThe Kirchhoff-Love hypothesis expresses a kinematic constraint that is assumed to be valid for the deformations of a three-dimensional body when one of its dimensions is much smaller than the other two, as is the case for plates. This hypothesis has a long history checkered with the vicissitudes of life: even its paternity has been questioned, and recent rigorous dimension-reduction tools (based on standard $\varGamma $ Γ -convergence) have proven to be incompatible with it. We find that an appropriately revised version of the Kirchhoff-Love hypothesis is a valuable means to derive a two-dimensional variational model for elastic plates from a three-dimensional nonlinear free-energy functional. The bending energies thus obtained for a number of materials also show to contain measures of stretching of the plate’s mid surface (alongside the expected measures of bending). The incompatibility with standard $\varGamma $ Γ -convergence also appears to be removed in the cases where contact with that method and ours can be made.


Nonlinearity ◽  
2009 ◽  
Vol 22 (12) ◽  
pp. 2919-2952 ◽  
Author(s):  
E A Carlen ◽  
M C Carvalho ◽  
R Esposito ◽  
J L Lebowitz ◽  
R Marra

2006 ◽  
Vol 16 (2) ◽  
pp. 233-264 ◽  
Author(s):  
E. A. Carlen ◽  
M. C. Carvalho ◽  
R. Esposito ◽  
J. L. Lebowitz ◽  
R. Marra

Author(s):  
François Alouges ◽  
Giovanni Di Fratta

The objective of this paper is to perform, by means of Γ - convergence and two-scale convergence , a rigorous derivation of the homogenized Gibbs–Landau free energy functional associated with a composite periodic ferromagnetic material, i.e. a ferromagnetic material in which the heterogeneities are periodically distributed inside the media. We thus describe the Γ -limit of the Gibbs–Landau free energy functional, as the period over which the heterogeneities are distributed inside the ferromagnetic body shrinks to zero.


2016 ◽  
Vol 18 (3) ◽  
pp. 1771-1785 ◽  
Author(s):  
Kazuo Takatsuka ◽  
Kentaro Matsumoto

We present a basic theory to study real-time chemical dynamics embedded in a statistically treated large environment. It is shown that dynamically treated molecules should run on the free-energy functional surface, if and only if the spatial gradients of temperature functional are all zero.


Author(s):  
Razvan-Dumitru Ceuca

We consider a Landau-de Gennes model for a connected cubic lattice scaffold in a nematic host, in a dilute regime. We analyse the homogenised limit for both cases in which the lattice of embedded particles presents or not cubic symmetry and then we compute the free effective energy of the composite material. In the cubic symmetry case, we impose different types of surface anchoring energy densities, such as quartic, Rapini-Papoular or more general versions, and, in this case, we show that we can tune any coefficient from the corresponding bulk potential, especially the phase transition temperature. In the case with loss of cubic symmetry, we prove similar results in which the effective free energy functional has now an additional term, which describes a change in the preferred alignment of the liquid crystal particles inside the domain. Moreover, we compute the rate of convergence for how fast the surface energies converge to the homogenised one and also for how fast the minimisers of the free energies tend to the minimiser of the homogenised free energy.


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