Displaying 121 – 140 of 284

Showing per page

Homogenization of highly oscillating boundaries and reduction of dimension for a monotone problem

Dominique Blanchard, Antonio Gaudiello (2010)

ESAIM: Control, Optimisation and Calculus of Variations

We investigate the asymptotic behaviour, as ε → 0, of a class of monotone nonlinear Neumann problems, with growth p-1 (p ∈]1, +∞[), on a bounded multidomain Ω ε N (N ≥ 2). The multidomain ΩE is composed of two domains. The first one is a plate which becomes asymptotically flat, with thickness hE in the xN direction, as ε → 0. The second one is a “forest" of cylinders distributed with ε-periodicity in the first N - 1 directions on the upper side of the plate. Each cylinder has a small...

Homogenization of linear parabolic equations with three spatial and three temporal scales for certain matchings between the microscopic scales

Tatiana Danielsson, Pernilla Johnsen (2021)

Mathematica Bohemica

In this paper we establish compactness results of multiscale and very weak multiscale type for sequences bounded in L 2 ( 0 , T ; H 0 1 ( Ω ) ) , fulfilling a certain condition. We apply the results in the homogenization of the parabolic partial differential equation ε p t u ε ( x , t ) - · ( a ( x ε - 1 , x ε - 2 , t ε - q , t ε - r ) u ε ( x , t ) ) = f ( x , t ) , where 0 < p < q < r . The homogenization result reveals two special phenomena, namely that the homogenized problem is elliptic and that the matching for which the local problem is parabolic is shifted by p , compared to the standard matching that gives rise to local parabolic...

Homogenization of locally stationary diffusions with possibly degenerate diffusion matrix

Rémi Rhodes (2009)

Annales de l'I.H.P. Probabilités et statistiques

This paper deals with homogenization of second order divergence form parabolic operators with locally stationary coefficients. Roughly speaking, locally stationary coefficients have two evolution scales: both an almost constant microscopic one and a smoothly varying macroscopic one. The homogenization procedure aims to give a macroscopic approximation that takes into account the microscopic heterogeneities. This paper follows [Probab. Theory Related Fields (2009)] and improves this latter work by...

Homogenization of many-body structures subject to large deformations

Philipp Emanuel Stelzig (2012)

ESAIM: Control, Optimisation and Calculus of Variations

We give a first contribution to the homogenization of many-body structures that are exposed to large deformations and obey the noninterpenetration constraint. The many-body structures considered here resemble cord-belts like they are used to reinforce pneumatic tires. We establish and analyze an idealized model for such many-body structures in which the subbodies are assumed to be hyperelastic with a polyconvex energy density and shall exhibit an initial brittle bond with their neighbors. Noninterpenetration...

Homogenization of many-body structures subject to large deformations

Philipp Emanuel Stelzig (2012)

ESAIM: Control, Optimisation and Calculus of Variations

We give a first contribution to the homogenization of many-body structures that are exposed to large deformations and obey the noninterpenetration constraint. The many-body structures considered here resemble cord-belts like they are used to reinforce pneumatic tires. We establish and analyze an idealized model for such many-body structures in which the subbodies are assumed to be hyperelastic with a polyconvex energy density and shall exhibit an...

Homogenization of micromagnetics large bodies

Giovanni Pisante (2004)

ESAIM: Control, Optimisation and Calculus of Variations

A homogenization problem related to the micromagnetic energy functional is studied. In particular, the existence of the integral representation for the homogenized limit of a family of energies ε ( m ) = Ω φ x , x ε , m ( x ) d x - Ω h e ( x ) · m ( x ) d x + 1 2 3 | u ( x ) | 2 d x of a large ferromagnetic body is obtained.

Homogenization of micromagnetics large bodies

Giovanni Pisante (2010)

ESAIM: Control, Optimisation and Calculus of Variations

A homogenization problem related to the micromagnetic energy functional is studied. In particular, the existence of the integral representation for the homogenized limit of a family of energies ε ( m ) = Ω φ x , x ε , m ( x ) d x - Ω h e ( x ) · m ( x ) d x + 1 2 3 | u ( x ) | 2 d x of a large ferromagnetic body is obtained.

Homogenization of monotone parabolic problems with an arbitrary number of spatial and temporal scales

Tatiana Danielsson, Liselott Flodén, Pernilla Johnsen, Marianne Olsson Lindberg (2024)

Applications of Mathematics

We prove a general homogenization result for monotone parabolic problems with an arbitrary number of microscopic scales in space as well as in time, where the scale functions are not necessarily powers of the scale parameter ε . The main tools for the homogenization procedure are multiscale convergence and very weak multiscale convergence, both adapted to evolution problems.

Homogenization of monotone parabolic problems with several temporal scales

Jens Persson (2012)

Applications of Mathematics

In this paper we homogenize monotone parabolic problems with two spatial scales and any number of temporal scales. Under the assumption that the spatial and temporal scales are well-separated in the sense explained in the paper, we show that there is an H-limit defined by at most four distinct sets of local problems corresponding to slow temporal oscillations, slow resonant spatial and temporal oscillations (the “slow” self-similar case), rapid temporal oscillations, and rapid resonant spatial and...

Homogenization of monotone systems of Hamilton-Jacobi equations

Fabio Camilli, Olivier Ley, Paola Loreti (2010)

ESAIM: Control, Optimisation and Calculus of Variations

In this paper we study homogenization for a class of monotone systems of first-order time-dependent periodic Hamilton-Jacobi equations. We characterize the Hamiltonians of the limit problem by appropriate cell problems. Hence we show the uniform convergence of the solution of the oscillating systems to the bounded uniformly continuous solution of the homogenized system.

Homogenization of Neumann problems for unbounded integral functionals

Luciano Carbone, Antonio Corbo Esposito, Riccardo De Arcangelis (1999)

Bollettino dell'Unione Matematica Italiana

Si studia l'omogeneizzazione di problemi di tipo Neumann per funzionali integrali del Calcolo delle Variazioni definiti su funzioni soggette a vincoli puntuali di tipo oscillante sul gradiente, in ipotesi minimali sui vincoli. I risultati ottenuti sono dedotti mediante l'introduzione di nuove tecniche di Γ -convergenza, unitamente ad un risultato di ricostruzione per funzioni affini a tratti, che permettono la dimostrazione di un teorema generale di omogeneizzazione per funzionali integrali a valori...

Homogenization of parabolic equations an alternative approach and some corrector-type results

Anders Holmbom (1997)

Applications of Mathematics

We extend and complete some quite recent results by Nguetseng [Ngu1] and Allaire [All3] concerning two-scale convergence. In particular, a compactness result for a certain class of parameterdependent functions is proved and applied to perform an alternative homogenization procedure for linear parabolic equations with coefficients oscillating in both their space and time variables. For different speeds of oscillation in the time variable, this results in three cases. Further, we prove some corrector-type...

Homogenization of periodic non self-adjoint problems with large drift and potential

Grégoire Allaire, Rafael Orive (2007)

ESAIM: Control, Optimisation and Calculus of Variations

We consider the homogenization of both the parabolic and eigenvalue problems for a singularly perturbed convection-diffusion equation in a periodic medium. All coefficients of the equation may vary both on the macroscopic scale and on the periodic microscopic scale. Denoting by ε the period, the potential or zero-order term is scaled as ε - 2 and the drift or first-order term is scaled as ε - 1 . Under a structural hypothesis on the first cell eigenvalue, which is assumed to admit a unique minimum in the...

Homogenization of periodic nonconvex integral functionals in terms of Young measures

Omar Anza Hafsa, Jean-Philippe Mandallena, Gérard Michaille (2006)

ESAIM: Control, Optimisation and Calculus of Variations

Homogenization of periodic functionals, whose integrands possess possibly multi-well structure, is treated in terms of Young measures. More precisely, we characterize the Γ -limit of sequences of such functionals in the set of Young measures, extending the relaxation theorem of Kinderlherer and Pedregal. We also make precise the relationship between our homogenized density and the classical one.

Homogenization of periodic nonconvex integral functionals in terms of Young measures

Omar Anza Hafsa, Jean-Philippe Mandallena, Gérard Michaille (2005)

ESAIM: Control, Optimisation and Calculus of Variations

Homogenization of periodic functionals, whose integrands possess possibly multi-well structure, is treated in terms of Young measures. More precisely, we characterize the Γ-limit of sequences of such functionals in the set of Young measures, extending the relaxation theorem of Kinderlherer and Pedregal. We also make precise the relationship between our homogenized density and the classical one.

Currently displaying 121 – 140 of 284