Modelli di transizione di fase con movimenti microscopici
Some quasivariational problems with memory
This note deals with a class of abstract quasivariational evolution problems that may include some memory effects. Under a suitable monotonicity framework, we provide a generalized existence result by means of a fixed point technique in ordered spaces. Finally, an application to the modeling of generalized kinematic hardening in plasticity is discussed.
Weighted energy-dissipation functionals for gradient flows
We investigate a global-in-time variational approach to abstract evolution by means of the functionals proposed by Mielke and Ortiz [ (2008) 494–516]. In particular, we focus on gradient flows in Hilbert spaces. The main result is the convergence of minimizers and approximate minimizers of these functionals to the unique solution of the gradient flow. Sharp convergence rates are provided and the convergence analysis is combined with time-discretization. Applications of the...
Some Nonlinear Evolution Problems in Mixed Form
This work deals with some abstract equations, either linear or nonlinear, arising from the so-called mixed formulation of PDEs of elliptic and parabolic type. This class of variational formulations turns out to be particularly relevant in connection with the development of finite elements approximations. We prove the well-posedness of both the stationary and the evolution problems.
Linearized plasticity is the evolutionary -limit of finite plasticity
We provide a rigorous justification of the classical linearization approach in plasticity. By taking the small-deformations limit, we prove via -convergence for rate-independent processes that energetic solutions of the quasi-static finite-strain elastoplasticity system converge to the unique strong solution of linearized elastoplasticity.
Weighted Inertia-Dissipation-Energy Functionals for Semilinear Equations
We address a global-in-time variational approach to semilinear PDEs of either parabolic or hyperbolic type by means of the so-called Weighted Inertia-Dissipation-Energy (WIDE) functional. In particular, minimizers of the WIDE functional are proved to converge, up to subsequences, to weak solutions of the limiting PDE. This entails the possibility of reformulating the limiting differential problem in terms of convex minimization. The WIDE formalism can be used in order to discuss parameters asymptotics...
Well-posedness of a thermo-mechanical model for shape memory alloys under tension
We present a model of the full thermo-mechanical evolution of a shape memory body undergoing a uniaxial tensile stress. The well-posedness of the related quasi-static thermo-inelastic problem is addressed by means of hysteresis operators techniques. As a by-product, details on a time-discretization of the problem are provided.
Weighted energy-dissipation functionals for gradient flows
We investigate a global-in-time variational approach to abstract evolution by means of the functionals proposed by Mielke and Ortiz [ (2008) 494–516]. In particular, we focus on gradient flows in Hilbert spaces. The main result is the convergence of minimizers and approximate minimizers of these functionals to the unique solution of the gradient flow. Sharp convergence rates are provided and the convergence analysis is combined with time-discretization. Applications of the...
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