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Teoria degli operatori intermedi e applicazioni: statica elastica con coefficienti discontinui, il problema misto e i problemi di trasmissione

Flavia Lanzara (1993)

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

Viene applicata la teoria della Nota I al problema al contorno dell'elastostatica quando sul contorno vengono prescritte condizioni miste. I coefficienti elastici sono supposti solo limitati e misurabili. Viene fatta un'analisi dettagliata per determinare l'operatore base. Si fa inoltre vedere come i problemi di trasmissione, relativi a due o più solidi elastici non isotropi e non omogenei incastrati l'uno nell'altro, rientrano nella teoria sviluppata nelle Note precedenti.

Teoria degli operatori intermedi e applicazioni: statica elastica con coefficienti discontinui, il problema degli spostamenti

Flavia Lanzara (1992)

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

Viene applicata la teoria della Nota I al problema al contorno dell'elastostatica quando sul contorno vengono prescritti spostamenti nulli. I coefficienti elastici sono supposti solo limitati e misurabili. Come problema base viene assunto l'analogo problema al contorno per un corpo isotropo omogeneo. Per un tale problema vengono esplicitamente costruiti l'operatore e la matrice di Green e le loro proprietà esaurientemente studiate, in modo tale che la teoria degli operatori intermedi, come sviluppata...

The assessment of the residual post-transient stresses in elastic-perfectly plastic solids subjected to cyclic loads

Castrenze Polizzotto (1993)

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

For elastic-perfectly plastic solids (or structures) subjected to quasi-static cyclic loads, variational methods are presented for the direct eyâluation of the post-transient residual stresses, that is, the residual stresses in the structure at the end of the transient response phase, consequence of the plastic strains therein produced and crucial to predict the subsequent steady structural behaviour. The problem of the evaluation of the number of cycles spanned by the transient response is also...

The dynamical Lame system : regularity of solutions, boundary controllability and boundary data continuation

M. I. Belishev, I. Lasiecka (2002)

ESAIM: Control, Optimisation and Calculus of Variations

The boundary control problem for the dynamical Lame system (isotropic elasticity model) is considered. The continuity of the “input → state” map in L 2 -norms is established. A structure of the reachable sets for arbitrary T > 0 is studied. In general case, only the first component u ( · , T ) of the complete state { u ( · , T ) , u t ( · , T ) } may be controlled, an approximate controllability occurring in the subdomain filled with the shear (slow) waves. The controllability results are applied to the problem of the boundary data continuation....

The dynamical Lame system: regularity of solutions, boundary controllability and boundary data continuation

M. I. Belishev, I. Lasiecka (2010)

ESAIM: Control, Optimisation and Calculus of Variations

The boundary control problem for the dynamical Lame system (isotropic elasticity model) is considered. The continuity of the “input → state" map in L2-norms is established. A structure of the reachable sets for arbitrary T>0 is studied. In general case, only the first component u ( · , T ) of the complete state { u ( · , T ) , u t ( · , T ) } may be controlled, an approximate controllability occurring in the subdomain filled with the shear (slow) waves. The controllability results are applied to the problem of the boundary data continuation....

The existence of a solution and a numerical method for the Timoshenko nonlinear wave system

Jemal Peradze (2004)

ESAIM: Mathematical Modelling and Numerical Analysis - Modélisation Mathématique et Analyse Numérique

The initial boundary value problem for a beam is considered in the Timoshenko model. Assuming the analyticity of the initial conditions, it is proved that the problem is solvable throughout the time interval. After that, a numerical algorithm, consisting of three steps, is constructed. The solution is approximated with respect to the spatial and time variables using the Galerkin method and a Crank–Nicholson type scheme. The system of equations obtained by discretization is solved by a version of...

The existence of a solution and a numerical method for the Timoshenko nonlinear wave system

Jemal Peradze (2010)

ESAIM: Mathematical Modelling and Numerical Analysis

The initial boundary value problem for a beam is considered in the Timoshenko model. Assuming the analyticity of the initial conditions, it is proved that the problem is solvable throughout the time interval. After that, a numerical algorithm, consisting of three steps, is constructed. The solution is approximated with respect to the spatial and time variables using the Galerkin method and a Crank–Nicholson type scheme. The system of equations obtained by discretization is solved by a version...

The impact of uncertain parameters on ratchetting trends in hypoplasticity

Chleboun, Jan, Runcziková, Judita, Krejčí, Pavel (2023)

Programs and Algorithms of Numerical Mathematics

Perturbed parameters are considered in a hypoplastic model of granular materials. For fixed parameters, the model response to a periodic stress loading and unloading converges to a limit state of strain. The focus of this contribution is the assessment of the change in the limit strain caused by varying model parameters.

The stability study of a plane engine

Rafał Kołodziej, Tomasz Nowicki (2000)

Applicationes Mathematicae

We study the dynamical properties of a plane engine vibrations modelled by a system of ODE.

Time splitting for wave equations in random media

Guillaume Bal, Lenya Ryzhik (2004)

ESAIM: Mathematical Modelling and Numerical Analysis - Modélisation Mathématique et Analyse Numérique

Numerical simulation of high frequency waves in highly heterogeneous media is a challenging problem. Resolving the fine structure of the wave field typically requires extremely small time steps and spatial meshes. We show that capturing macroscopic quantities of the wave field, such as the wave energy density, is achievable with much coarser discretizations. We obtain such a result using a time splitting algorithm that solves separately and successively propagation and scattering in the simplified...

Currently displaying 361 – 380 of 449