Shells with thickness distension

A deductive approach to shell theory is presented, within which a shell is regarded as a constrained three-dimensional continuum with special body str ucture: more precisely, admissible deformations are given a restricted form , presumed to be consistent with the special shape and partitionability of a shell-like body. In addition to the standard balance equations of forces and torques, an ext ra balance equation is derived, allowing for a description of dilatation or contraction in the thickness dimension. As an illustrative application, th e foe oscillations of linearly elastic plates - in particular, thickness-di stension waves - are studied. (C) 2001 Published by Elsevier Science Ltd. A ll rights reserved.