This work is focused on the equationL 2 (0,1) ∂ xx u = f describing the motion of an extensible viscoelastic beam. Under suitable boundary conditions, the related dynamical system in the history space framework is shown to possess a global attractor of optimal regularity. The result is obtained by exploiting an appropriate decomposition of the solution semigroup, together with the existence of a Lyapunov functional.

In this paper we study the long-term dynamics of a nonlinear suspension bridge system. The road bed and the main cable are modeled as a nonlinear beam and a vibrating string, respectively, and their coupling is carried out by one-sided springs. First, we scrutinize the set of stationary solutions, which turns out to be nontrivial when the axial load exceeds some critical value. Then, we prove the existence of a bounded global attractor of optimal regularity and we give its characterization in terms of the steady states of the problem.

This work is focused on the doubly nonlinear equation , whose solutions represent the bending motion of an extensible, elastic bridge suspended by continuously distributed cables which are flexible and elastic with stiffness . When the ends are pinned, long-term dynamics is scrutinized for arbitrary values of axial load and stiffness . For a general external source , we prove the existence of bounded absorbing sets. When is time-independent, the related semigroup of solutions is shown to possess the global attractor of optimal regularity and its characterization is given in terms of the steady states of the problem.

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a b s t r a c tIn this paper we study the long-term dynamics of a doubly nonlinear abstract system which involves a single differential operator to different powers. For a special choice of the nonlinear terms, the system describes the motion of a suspension bridge where the road bed and the main cable are modeled as a nonlinear beam and a vibrating string, respectively, and their coupling is carried out by nonlinear springs. The set of stationary solutions turns out to be nonempty and bounded. As the external loads vanish, the null solution of the system is proved to be exponentially stable provided that the axial load does not exceed some critical value. Finally, we prove the existence of a bounded global attractor of optimal regularity in connection with an arbitrary axial load and quite general nonlinear terms.

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In this paper we present two basic one-dimensional models for the temperature-induced phase-changes in a ferromagnetic material. In the framework of the Ginzburg-Landau theory, we construct suitable thermodynamic potentials from which thermodynamically-consistent evolution equations for the magnetization are derived. For both soft and hard materials these models account for saturation and provide an effective description of the transition from paramagnetic to ferromagnetic regimes by displaying the onset of hysteresis loops when the temperature decreases below the Curie critical value. The temperature enters the model as a parameter by way of the magnetic susceptibility. Such a dependence is discussed in order to comply with both Bloch's law (below the critical value) and Curie-Weiss law (far above the critical value). Focusing on uniform processes, numerical simulations of the magnetic responses at different temperatures are performed