BOUNDARY OBSERVABILITY, CONTROLLABILITY AND STABILIZATION OF LINEAR ELASTODYNAMIC SYSTEMS

We study homogeneous but not necessarily isotropic linear elastodynami c systems. Applying the Hilbert Uniqueness Method (HUM), we establish their boundary observability and their exact boundary controllability. Then we construct boundary feedbacks leading to arbitrarily large ene rgy decay rates. Finally, under some geometrical conditions, we prove that a ''natural'' boundary feedback leads also to exponentiel energy decay.