Table of contents of volume 35 (2006)
Teoremi di esistenza e unicità in elastostatica finita
Teoria degli operatori intermedi e applicazioni: il problema non autoaggiunto
Lo scopo del lavoro è di mostrare come nel quadro della teoria sviluppata nelle Note precedenti è possibile includere problemi non autoaggiunti. Viene mostrato che questo è possibile quando si considera il problema di Dirichlet per un'equazione ellittica del secondo ordine non autoaggiunta con coefficienti limitati e misurabili. Sono assai probabili estensioni a problemi più generali.
Teoria degli operatori intermedi e applicazioni: statica elastica con coefficienti discontinui, il problema delle tensioni
Viene applicata la teoria della Nota I al problema al contorno dell'elastostatica quando sul contorno vengono prescritte forze nulle. I coefficienti elastici sono supposti solo limitati e misurabili. Viene fatta un'analisi dettagliata per determinare l'operatore base.
Teoria degli operatori intermedi e applicazioni: statica elastica con coefficienti discontinui, il problema misto e i problemi di trasmissione
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
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
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 comparative study of vibration control of flexible structure using smart materials.
The convergence of a Galerkin approximation scheme for an extensible beam
The dynamical Lame system : regularity of solutions, boundary controllability and boundary data continuation
The boundary control problem for the dynamical Lame system (isotropic elasticity model) is considered. The continuity of the “input state” map in -norms is established. A structure of the reachable sets for arbitrary is studied. In general case, only the first component of the complete state 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
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 of the complete state 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 dynamics of a tied body against an obstacle
The existence of a solution and a numerical method for the Timoshenko nonlinear wave system
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
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 Fourier method in three-dimensional boundary-contact dynamic problems of elasticity.
The global solubility of problems of nonlinear vibrations of plates on nonlinear foundations.
The impact of uncertain parameters on ratchetting trends in hypoplasticity
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
We study the dynamical properties of a plane engine vibrations modelled by a system of ODE.
The transversal creeping vibrations of a nonhomogeneous beam with fractional derivative order constitutive relation.
Thermal stresses in an initially stressed circular cylinder with a smooth rigid insulating cover on the curved surface