Some remarks on a result of Talenti
Sottopotenziali energia libera per l'isteresi meccanica
This paper deals with free-energy lower-potentials for some rate-independent one-dimensional models of isothermal finite elastoplasticity proposed in [1]. Extending the thermodynamic arguments of Coleman and Owen [3] to large deformations, the existence, non-uniqueness and regularity of free-energy as function of state are deduced rather than assumed. This approach, along with some optimal control techniques, enables us to construct maximum and minimum free-energy functions and a wide class of differentiable...
Space-time discontinuous Galerkin method for the solution of fluid-structure interaction
The paper is concerned with the application of the space-time discontinuous Galerkin method (STDGM) to the numerical solution of the interaction of a compressible flow and an elastic structure. The flow is described by the system of compressible Navier-Stokes equations written in the conservative form. They are coupled with the dynamic elasticity system of equations describing the deformation of the elastic body, induced by the aerodynamical force on the interface between the gas and the elastic...
Spatial heterogeneity in 3D-2D dimensional reduction
A justification of heterogeneous membrane models as zero-thickness limits of a cylindral three-dimensional heterogeneous nonlinear hyperelastic body is proposed in the spirit of Le Dret (1995). Specific characterizations of the 2D elastic energy are produced. As a generalization of Bouchitté et al. (2002), the case where external loads induce a density of bending moment that produces a Cosserat vector field is also investigated. Throughout, the 3D-2D dimensional reduction is viewed as a problem...
Spatial heterogeneity in 3D-2D dimensional reduction
A justification of heterogeneous membrane models as zero-thickness limits of a cylindral three-dimensional heterogeneous nonlinear hyperelastic body is proposed in the spirit of Le Dret (1995). Specific characterizations of the 2D elastic energy are produced. As a generalization of Bouchitté et al. (2002), the case where external loads induce a density of bending moment that produces a Cosserat vector field is also investigated. Throughout, the 3D-2D dimensional reduction is viewed as a problem...
Stabilisation exponentielle d’une équation des poutres d’Euler-Bernoulli à coefficients variables
Dans ce travail, nous étudions la propriété de base de Riesz et la stabilisation exponentielle pour une équation des poutres d’Euler-Bernoulli à coefficients variables sous un contrôle frontière linéaire dépendant de la position (resp. l’angle de rotation), de la vitesse et de la vitesse de rotation dans le contrôle force (resp. moment). Nous montrons qu’il existe une suite de fonctions propres généralisées qui forme une base de Riesz de l’espace d’énergie considéré, et qu’il y a stabilité exponentielle...
Stability of a Finite Thermoelastic Deformation of a Fibre-Reinforced Massive Slab
Stabilization of Berger–Timoshenko’s equation as limit of the uniform stabilization of the von Kármán system of beams and plates
We consider a dynamical one-dimensional nonlinear von Kármán model for beams depending on a parameter and study its asymptotic behavior for large, as . Introducing appropriate damping mechanisms we show that the energy of solutions of the corresponding damped models decay exponentially uniformly with respect to the parameter . In order for this to be true the damping mechanism has to have the appropriate scale with respect to . In the limit as we obtain damped Berger–Timoshenko beam models...
Stabilization of Berger–Timoshenko's equation as limit of the uniform stabilization of the von Kármán system of beams and plates
We consider a dynamical one-dimensional nonlinear von Kármán model for beams depending on a parameter ε > 0 and study its asymptotic behavior for t large, as ε → 0. Introducing appropriate damping mechanisms we show that the energy of solutions of the corresponding damped models decay exponentially uniformly with respect to the parameter ε. In order for this to be true the damping mechanism has to have the appropriate scale with respect to ε. In the limit as ε → 0 we obtain damped Berger–Timoshenko...
Strong unique continuation for the Lamé system with Lipschitz coefficients in three dimensions
This paper studies the strong unique continuation property for the Lamé system of elasticity with variable Lamé coefficients λ, µin three dimensions, whereλ and μ are Lipschitz continuous and V∈L∞. The method is based on the Carleman estimate with polynomial weights for the Lamé operator.
Strong unique continuation for the Lamé system with Lipschitz coefficients in three dimensions*
This paper studies the strong unique continuation property for the Lamé system of elasticity with variable Lamé coefficients λ, µ in three dimensions, where λ and μ are Lipschitz continuous and V∈L∞. The method is based on the Carleman estimate with polynomial weights for the Lamé operator.
Su alcune classi di potenziali termodinamici come conseguenza dell'esistenza di particolari onde di discontinuità nella meccanica dei continui con deformazioni finite
Su l'esistenza della soluzione per la flessione delle piastre elastiche micropolari
Sufficient conditions for the validity of the Cauchy-Born rule close to
The Cauchy–Born rule provides a crucial link between continuum theories of elasticity and the atomistic nature of matter. In its strongest form it says that application of affine displacement boundary conditions to a monatomic crystal will lead to an affine deformation of the whole crystal lattice. We give a general condition in arbitrary dimensions which ensures the validity of the Cauchy–Born rule for boundary deformations which are close to rigid motions. This generalizes results of Friesecke...
Sui continui di Cosserat con rotazioni libere
Sui materiali elastici con memoria
Viene esposto il punto di vista dell'autore rispetto ai modelli matematici dell'elasticità ereditaria. Particolare rilievo viene dato all'influenza della topologia dello spazio delle funzioni ammissibili sui concetti fondamentali della teoria.
Sui teoremi di reciprocità dell'elasticità lineare classica in domini non limitati
We extend the well-known reciprocal theorems of linear elasticity to unbounded domains. The theorems do not require that the elastic body is isotropic and homogeneous.
Sul principio di indifferenza materiale
Sul problema del rimbalzo in un insieme convesso
In the present paper we seek the bounce trajectories in a convex set which assume assigned positions in two fixed time instants. We find sufficient conditions in order to obtain the existence of infinitely many bounce trajectories.
Sul problema di contatto tra piastre
Si studia il problema di contatto tra due piastre sottili linearmente elastiche, incastrate al bordo, poste inizialmente a distanza e trasversalmente caricate. Si fa l'ipotesi che il contatto tra le due piastre, a deformazione avvenuta, sia privo di attrito. Il problema dell'equilibrio elastico è formulato per via variazionale in termini di lavori virtuali o, equivalentemente, di minimo del funzionale dell'energia. Il quadro analitico di riferimento è quello della teoria delle disequazioni variazionali...