Controllability of the linear system of thermoelasticity

We prove that the linear system of thermoelasticity is controllable in the following sense: If the control time is large enough and we act in the equations of displacement by means of a control supported in a neighborhood of the boundary of the thermoelastic body, then we may control exactly the displacement and simultaneously the temperature in an approximate way. The method of proof combines: (i) A decoupling result for the system of thermoelasticity due to D. Henry, O. Lopes and A. Perissinitto, (ii) the variational approach to controllability developed recently by C. Fabre, J. P. Puel and the author and (iii) some new observability inequalities for the system of thermoelasticity.