Dynamic stabilization of systems via decoupling techniques
Dynamic stabilization of systems via decoupling techniques
We give sufficient conditions which allow the study of the exponential stability of systems closely related to the linear thermoelasticity systems by a decoupling technique. Our approach is based on the multipliers technique and our result generalizes (from the exponential stability point of view) the earlier one obtained by Henry et al.
Dynamics of Biomembranes: Effect of the Bulk Fluid
We derive a biomembrane model consisting of a fluid enclosed by a lipid membrane. The membrane is characterized by its Canham-Helfrich energy (Willmore energy with area constraint) and acts as a boundary force on the Navier-Stokes system modeling an incompressible fluid. We give a concise description of the model and of the associated numerical scheme. We provide numerical simulations with emphasis on the comparisons between different types of flow:...
Effect of rotation and relaxation times on plane waves in generalized thermo-visco-elasticity.
Effects of In-plane Elastic Stress and Normal External Stress on Viscoelastic Thin Film Stability
Motivated by recent experiments on the electro-hydrodynamic instability of spin-cast polymer films, we study the undulation instability of a thin viscoelastic polymer film under in-plane stress and in the presence of either a close by contactor or an electric field, both inducing a normal stress on the film surface. We find that the in-plane stress affects both the typical timescale of the instability and the unstable wavelengths. The film stability...
Ein Gewisses Randproblem aus der Theorie der Wärmeleitfähigkeit
Elastic wave propagation in fluid-saturated porous media. Part I. The existence and uniqueness theorems
Elastic wave propagation in fluid-saturated porous media. Part II. The Galerkin procedures
Electronic properties of superconductor-semiconductor mesoscopic device.
Equivalent Boundary Conditions for an Elasto-Acoustic Problem set in a Domain with a Thin Layer
We present equivalent conditions and asymptotic models for the diffraction problem of elastic and acoustic waves in a solid medium surrounded by a thin layer of fluid medium. Due to the thinness of the layer with respect to the wavelength, this problem is well suited for the notion of equivalent conditions and the effect of the fluid medium on the solid is as a first approximation local. We derive and validate equivalent conditions up to the fourth order for the elastic displacement. These conditions...
Esistenza e unicità della soluzione nella statica di solidi termoelastici incomprimibili
In this work we prove that the thermoelastic equilibrium problem in the context of the linear theory for thermoelastic incompressible solids has one and only one solution.
Étude de deux schémas numériques pour les équations de la thermoélasticité
Eulerian formulation and level set models for incompressible fluid-structure interaction
This paper is devoted to Eulerian models for incompressible fluid-structure systems. These models are primarily derived for computational purposes as they allow to simulate in a rather straightforward way complex 3D systems. We first analyze the level set model of immersed membranes proposed in [Cottet and Maitre, Math. Models Methods Appl. Sci.16 (2006) 415–438]. We in particular show that this model can be interpreted as a generalization of so-called Korteweg fluids. We then extend this model...
Evolution of fluid-fluid interface in porous media as the model of gas-oil fields.
Exact controllability in fluid – solid structure: The Helmholtz model
A model representing the vibrations of a fluid-solid coupled structure is considered. Following Hilbert Uniqueness Method (HUM) introduced by Lions, we establish exact controllability results for this model with an internal control in the fluid part and there is no control in the solid part. Novel features which arise because of the coupling are pointed out. It is a source of difficulty in the proof of observability inequalities, definition of weak solutions and the proof of controllability...
Exact controllability in fluid–solid structure : the Helmholtz model
A model representing the vibrations of a fluid-solid coupled structure is considered. Following Hilbert Uniqueness Method (HUM) introduced by Lions, we establish exact controllability results for this model with an internal control in the fluid part and there is no control in the solid part. Novel features which arise because of the coupling are pointed out. It is a source of difficulty in the proof of observability inequalities, definition of weak solutions and the proof of controllability results....
Exact controllability of an elastic membrane coupled with a potential fluid
We consider the problem of boundary control of an elastic system with coupling to a potential equation. The potential equation represents the linearized motions of an incompressible inviscid fluid in a cavity bounded in part by an elastic membrane. Sufficient control is placed on a portion of the elastic membrane to insure that the uncoupled membrane is exactly controllable. The main result is that if the density of the fluid is sufficiently small, then the coupled system is exactly controllable....
Exact relativistic theory of wave propagation in prestressed nonlinear elastic solids
Excitation of shear waves in a piezoceramic medium with partially electrodized tunnel openings strengthened by a rigid stringer.
Existence and continuous dependence results in the dynamical theory of piezoelectricity
The paper is concerned with the dynamical theory of linear piezoelectricity. First, an existence theorem is derived. Then, the continuous dependence of the solutions upon the initial data and body forces is investigated.