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On a reliable solution of a Volterra integral equation in a Hilbert space

Igor Bock, Ján Lovíšek (2003)

Applications of Mathematics

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 superconvergent finite element scheme for elliptic systems. II. Boundary conditions of Newton's or Neumann's type

Ivan Hlaváček, Michal Křížek (1987)

Aplikace matematiky

A simple superconvergent scheme for the derivatives of finite element solution is presented, when linear triangular elements are employed to solve second order elliptic systems with boundary conditions of Newton’s or Neumann’s type. For bounded plane domains with smooth boundary the local O ( h 3 / 2 ) -superconvergence of the derivatives in the L 2 -norm is proved. The paper is a direct continuations of [2], where an analogous problem with Dirichlet’s boundary conditions is treated.

On a superconvergent finite element scheme for elliptic systems. III. Optimal interior estimates

Ivan Hlaváček, Michal Křížek (1987)

Aplikace matematiky

Second order elliptic systems with boundary conditions of Dirichlet, Neumann’s or Newton’s type are solved by means of linear finite elements on regular uniform triangulations. Error estimates of the optimal order O ( h 2 ) are proved for the averaged gradient on any fixed interior subdomain, provided the problem under consideration is regular in a certain sense.

On a superconvergent finite element scheme for elliptic systems. I. Dirichlet boundary condition

Ivan Hlaváček, Michal Křížek (1987)

Aplikace matematiky

Second order elliptic systems with Dirichlet boundary conditions are solved by means of affine finite elements on regular uniform triangulations. A simple averagign scheme is proposed, which implies a superconvergence of the gradient. For domains with enough smooth boundary, a global estimate O ( h 3 / 2 ) is proved in the L 2 -norm. For a class of polygonal domains the global estimate O ( h 2 ) can be proven.

On a transmission problem in elasticity

Christodoulos Athanasiadis, Ioannis G. Stratis (1998)

Annales Polonici Mathematici

The transmission problem for the reduced Navier equation of classical elasticity, for an infinitely stratified scatterer, is studied. The existence and uniqueness of solutions is proved. Moreover, an integral representation of the solution is constructed, for both the near and the far field.

On a type of Signorini problem without friction in linear thermoelasticity

Jiří Nedoma (1983)

Aplikace matematiky

In the paper the Signorini problem without friction in the linear thermoelasticity for the steady-state case is investigated. The problem discussed is the model geodynamical problem, physical analysis of which is based on the plate tectonic hypothesis and the theory of thermoelasticity. The existence and unicity of the solution of the Signorini problem without friction for the steady-state case in the linear thermoelasticity as well as its finite element approximation is proved. It is known that...

On a variational problem arising in crystallography

Alexander J. Zaslavski (2007)

ESAIM: Control, Optimisation and Calculus of Variations

We study a variational problem which was introduced by Hannon, Marcus and Mizel [ESAIM: COCV9 (2003) 145–149] to describe step-terraces on surfaces of so-called “unorthodox” crystals. We show that there is no nondegenerate intervals on which the absolute value of a minimizer is π / 2 identically.

On an elasto-dynamic evolution equation with non dead load and friction

Oanh Chau (2006)

Applications of Mathematics

In this paper, we are interested in the dynamic evolution of an elastic body, acted by resistance forces depending also on the displacements. We put the mechanical problem into an abstract functional framework, involving a second order nonlinear evolution equation with initial conditions. After specifying convenient hypotheses on the data, we prove an existence and uniqueness result. The proof is based on Faedo-Galerkin method.

On an interaction of two elastic bodies: analysis and algorithms

Ivona Svobodová (2012)

Applications of Mathematics

The paper deals with existence and uniqueness results and with the numerical solution of the nonsmooth variational problem describing a deflection of a thin annular plate with Neumann boundary conditions. Various types of the subsoil and the obstacle which influence the plate deformation are considered. Numerical experiments compare two different algorithms.

On an inversion formula of certain Laplace transforms in dissipative wave propagation

Pasquale Renno (1981)

Atti della Accademia Nazionale dei Lincei. Classe di Scienze Fisiche, Matematiche e Naturali. Rendiconti Lincei. Matematica e Applicazioni

Si determina una formula di inversione di alcune trasformate di Laplace che intervengono nell’analisi formale di problemi al contorno relativi ad una classe di mezzi dissipativi. Le espressioni esplicite proposte definiscono funzioni analitiche a decrescenza rapida dotate di numerose proprietà di massimo, utili anche all’analisi di problemi unilaterali.

On Asymptotic Theory of Beams, Plates and Shells

L.A. Aghalovyan, M.L. Aghalovyan (2016)

Curved and Layered Structures

Bases of asymptotic theory of beams, plates and shells are stated. The comparison with classic theory is conducted. New classes of thin bodies problems, for which hypotheses of classic theory are not applicable, are considered. By the asymptotic method effective solutions of these problems are obtained. The effectiveness of the asymptotic method for finding solutions of as static, as well as dynamic problems of beams, plates and shells is shown.

On asymptotics of solutions and eigenvalues of the boundary value problem with rapidly alternating boundary conditions for the system of elasticity

Olga A. Oleinik, Gregory Chechkin (1996)

Atti della Accademia Nazionale dei Lincei. Classe di Scienze Fisiche, Matematiche e Naturali. Rendiconti Lincei. Matematica e Applicazioni

Boundary value problems for the system of linear elasticity with rapidly alternating boundary conditions are studied and asymptotic behavior of solutions is considered when a small parameter, which defines the oscillation of the boundary conditions, tends to zero. Estimates for the difference between such solutions and solutions of the limit problem are given.

On Cauchy's stress theorem

Miroslav Šilhavŷ (1990)

Atti della Accademia Nazionale dei Lincei. Classe di Scienze Fisiche, Matematiche e Naturali. Rendiconti Lincei. Matematica e Applicazioni

In this work a new proof of the theorem of Cauchy on the existence of the stress tensor is given which does not use the tetrahedron argument.

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