Geometry of constraint manifolds and wave propagation in internally constrained elastic bodies

The implications of the non-Euclidean structure of constraint manifolds on differentiation of the stress in internally constrained elastic bodies are examined, and the equations governing propagation of acceleration waves in such bodies are deduced differentiating the reactive stress consistently with the assumption that it does no work in any admissible motion. This yields a treatment of the subject in which the presence of internal constraints imposes restrictions on the set of possible amplitudes of waves but the condition for local existence of waves, that amplitudes must satisfy, is of the same type as that for bodies free from internal constraints, in the sense that it depends on the properties of the response map of the material and is independent of reactive stress.