Analyticity, hyperbolicity and uniform stability of semigroups arising in models of composite beams

We examine the stability properties of a sandwich beam consisting of two ou ter layers and a thin core The outer layers are modeled as Euler Bernoulli beams and the inner core provides both elastic and viscous resistance to sh earing. We show for both clamped and hinged boundary conditions that (i) if rotational inertia terms are neglected, the model is described by an analy tic semigroup, and (ii) if rotational inertia is retained in the outer laye rs, the model is uniformly exponentially stable.