Nonlinear transmission problem with a dissipative boundary condition of memory type.
Numerical analysis of a frictionless viscoelastic piezoelectric contact problem
In this work, we consider the quasistatic frictionless contact problem between a viscoelastic piezoelectric body and a deformable obstacle. The linear electro-viscoelastic constitutive law is employed to model the piezoelectric material and the normal compliance condition is used to model the contact. The variational formulation is derived in a form of a coupled system for the displacement and electric potential fields. An existence and uniqueness result is recalled. Then, a fully discrete scheme...
Numerical Analysis of Evolution Problems in Nonlinear Small Strains Elastoviscoplasticity.
Numerical analysis of history-dependent quasivariational inequalities with applications in contact mechanics
A new class of history-dependent quasivariational inequalities was recently studied in [M. Sofonea and A. Matei, History-dependent quasivariational inequalities arising in contact mechanics. Eur. J. Appl. Math. 22 (2011) 471–491]. Existence, uniqueness and regularity results were proved and used in the study of several mathematical models which describe the contact between a deformable body and an obstacle. The aim of this paper is to provide numerical analysis of the quasivariational inequalities...
Numerical analysis of the quasistatic thermoviscoelastic thermistor problem
In this work, the quasistatic thermoviscoelastic thermistor problem is considered. The thermistor model describes the combination of the effects due to the heat, electrical current conduction and Joule's heat generation. The variational formulation leads to a coupled system of nonlinear variational equations for which the existence of a weak solution is recalled. Then, a fully discrete algorithm is introduced based on the finite element method to approximate the spatial variable and an Euler scheme...
Numerical exponential decay to dissipative Bresse system.
Numerical Treatment of Integro-Differential Equations with a Certain Maximum Propert.
On a 1-D model of stress relaxation in an annealed glass
A 1-D model of a slab of glass of a small thickness is considered. The governing equations are those of the classical 1-D linear viscoelasticity. A load due to the temperature gradients is assumed. The aim is to model the process called annealing. It is shown that an additional load due to structural strain is crucial for the success of the model. Algorithms of a numerical solution of the governing equations are proposed. Numerical results are presented and commented.
On a contact problem for a viscoelastic von Kármán plate and its semidiscretization
We deal with the system describing moderately large deflections of thin viscoelastic plates with an inner obstacle. In the case of a long memory the system consists of an integro-differential 4th order variational inequality for the deflection and an equation with a biharmonic left-hand side and an integro-differential right-hand side for the Airy stress function. The existence of a solution in a special case of the Dirichlet-Prony series is verified by transforming the problem into a sequence of...
On a global in time existence theorem of smooth solutions to an nonlinear wave equation with viscosity.
On a reliable solution of a Volterra integral equation in a Hilbert space
We consider a class of Volterra-type integral equations in a Hilbert space. The operators of the equation considered appear as time-dependent functions with values in the space of linear continuous operators mapping the Hilbert space into its dual. We are looking for maximal values of cost functionals with respect to the admissible set of operators. The existence of a solution in the continuous and the discretized form is verified. The convergence analysis is performed. The results are applied to...
On a shock problem involving a nonlinear viscoelastic bar.
On implicit constitutive theories
In classical constitutive models such as the Navier-Stokes fluid model, and the Hookean or neo-Hookean solid models, the stress is given explicitly in terms of kinematical quantities. Models for viscoelastic and inelastic responses on the other hand are usually implicit relationships between the stress and the kinematical quantities. Another class of problems wherein it would be natural to develop implicit constitutive theories, though seldom resorted to, are models for bodies that are constrained....
On one mathematical model of creep in superalloys
In a new micromechanical approach to the prediction of creep flow in composites with perfect matrix/particle interfaces, based on the nonlinear Maxwell viscoelastic model, taking into account a finite number of discrete slip systems in the matrix, has been suggested; high-temperature creep in such composites is conditioned by the dynamic recovery of the dislocation structure due to slip/climb motion of dislocations along the matrix/particle interfaces. In this article the proper formulation of the...
On Operators with Bounded Imaginary Powers in Banach Spaces.
On some viscoelastic models
Sia un sistema linearmente viscoelastico, omogeneo ed isotropo, caratterizzato dalla funzione di memoria , tipica di numerosi polimeri solidi. Si dimostra che la soluzione fondamentale dell’operatore integrodifferenziale che descrive i moti di è, in ogni punto del suo supporto, maggiorata da quella relativa ad un opportuno solido standard Di conseguenza, è possibile applicare all’analisi qualitativa dei moti di alcuni risultati stabiliti in [10], quali proprietà asintotiche, principi...
On the analysis of a viscoplastic contact problem with time dependent Tresca's friction law.
On the asymptotic behaviour of a solution of a differential equation in a Hilbert space
On the buckling of a viscoelastic rod
On the Cauchy problem in linear viscoelasticity
Con riferimento all’operatore integrodifferenziale della viscoelasticità lineare nella formulazione creep, si determina la soluzione fondamentale in corrispondenza di un’arbitraria funzione di memoria. Di conseguenza viene risolto esplicitamente il problema di Cauchy relativo al moto unidimensionale di un sistema viscoelastico , omogeneo ed isotropo, determinato da dati iniziali e storia di stress comunque prefissati. Successivamente, nell’ambito di opportune ipotesi di memoria labile, si dimostrano...