Flexible plate and foundation modelling.
Free energy and internal variables in linear viscoelasticity
In connection with the determination of the free energy functional for the viscoelastic stress tensor, a viscoelastic material is considered as described by a material with internal variables. In this framework the free energy is uniquely determined. It proves to be the minimal one in the class of thermodynamically admissible free energies.
Generalized Fractional Calculus With Application in Mechanics
Global existence and energy decay of solutions to a Bresse system with delay terms
We consider the Bresse system in bounded domain with delay terms in the internal feedbacks and prove the global existence of its solutions in Sobolev spaces by means of semigroup theory under a condition between the weight of the delay terms in the feedbacks and the weight of the terms without delay. Furthermore, we study the asymptotic behavior of solutions using multiplier method.
Global existence for a nuclear fluid in one dimension: the case
We consider a simplified one-dimensional thermal model of nuclear matter, described by a system of Navier-Stokes-Poisson type, with a non monotone equation of state due to an effective nuclear interaction. We prove the existence of globally defined (large) solutions of the corresponding free boundary problem, with an exterior pressure which is not required to be positive, provided sufficient thermal dissipation is present. We give also a partial description of the asymptotic behaviour of the system,...
Global in time solvability of the initial boundary value problem for some nonlinear dissipative evolution equations
The global in time solvability of the one-dimensional nonlinear equations of thermoelasticity, equations of viscoelasticity and nonlinear wave equations in several space dimensions with some boundary dissipation is discussed. The blow up of the solutions which might be possible even for small data is excluded by allowing for a certain dissipative mechanism.
Global Regular Solutions for the Dynamic Antiplane Shear Problem in Nonlinear Viscoelasticity.
I difficili rapporti fra l'Analisi funzionale e la Fisica Matematica
— Si mostra come la scelta di una topologia nello spazio delle funzioni ammissibili, in taluni problemi, influenzi i relativi risultati. Vengono mostrati tre esempi. Due tratti dall'Analisi matematica pura: uno riguardante la stabilità della soluzione di un'equazione integrale di Volterra e l'altro il problema di Cauchy per l'equazione di Laplace come «problema ben posto». Il terzo esempio è relativo alla Fisica matematica, precisamente al «Principio della Memoria evanescente» in Viscoelasticità....
Identification of hysteric control influence operators representing smart actuators. I: Formulation.
Il problema dinamico della viscoelasticità lineare : unicità per le soluzioni illimitate nel remoto passato
Implicit constitutive solution scheme for Mohr-Coulomb plasticity
This contribution summarizes an implicit constitutive solution scheme of the elastoplastic problem containing the Mohr-Coulomb yield criterion, a nonassociative flow rule, and a nonlinear isotropic hardening. The presented scheme builds upon the subdifferential formulation of the flow rule leading to several improvements. Mainly, it is possible to detect a position of the unknown stress tensor on the Mohr-Coulomb pyramid without blind guesswork. Further, a simplified construction of the consistent...
Initial boundary value problem for a system in elastodynamics with viscosity.
Inverse problems for memory kernels by Laplace transform methods.
Long time behaviour of a Cahn-Hilliard system coupled with viscoelasticity
The long-time behaviour of a unique regular solution to the Cahn-Hilliard system coupled with viscoelasticity is studied. The system arises as a model of the phase separation process in a binary deformable alloy. It is proved that for a sufficiently regular initial data the trajectory of the solution converges to the ω-limit set of these data. Moreover, it is shown that every element of the ω-limit set is a solution of the corresponding stationary problem.
Multipolar viscoelastic materials and the symmetry of the coefficients of viscosity
The integral constitutive equations of a multipolar viscoelastic material are analyzed from the thermodynamic point of view. They are shown to be approximated by those of the differential-type viscous materials when the processes are slow. As a consequence of the thermodynamic compatibility of the viscoelastic model, the coefficients of viscosity of the approximate viscous model are shown to have an Onsager-type symmetry. This symmetry was employed earlier in the proof of the existence of solutions...
Multiscale modelling of sound propagation through the lung parenchyma
In this paper we develop and study numerically a model to describe some aspects of sound propagation in the human lung, considered as a deformable and viscoelastic porous medium (the parenchyma) with millions of alveoli filled with air. Transmission of sound through the lung above 1 kHz is known to be highly frequency-dependent. We pursue the key idea that the viscoelastic parenchyma structure is highly heterogeneous on the small scale ε and use two-scale homogenization techniques to derive effective...
Non unicità dell'energia libera per materiali viscoelastici
La non unicità dell'energia libera per un materiale viscoelastico di tipo «rate» viene provata mediante la determinazione di un controesempio.
Nonlinear hyperbolic equations with dissipative temporal and spatial non-local memory.
Nonlinear modeling of cables with flexural stiffness.
Nonlinear transmission problem with a dissipative boundary condition of memory type.