TRANSIENT WAVES IN INHOMOGENEOUS ELASTIC SHELLS OF VARIABLE THICKNESS

This paper considers the problem of transient wave propagation in Cosserat shells of variable thickness, the inhomogeneous material of which is linearly elastic and isotropic. We do not say that the shells are isotropic because varying thickness causes behaviour characteristic of anisotropy despite the material's being isotropic. The methods of rays and of singular wave curves are combined to find and integrate the transport equations governing growth-decay behaviour of the six possible wave modes. Conditions on material parameters, thickness variation, and wave geometry are obtained for various different uncouplings of the wave modes. Some special cases of propagation conditions and of decay equations are worked out in detail. © 1990 Springer-Verlag.