Alternative spatial behaviour in the incompressible linear elastic prismatic constrained cylinder

Differential inequalities are derived for two cross-sectional energy fluxes. Integration establishes exponential growth and decay estimates for the cross-sectional mean square displacement, displacement gradient and pressure. The conclusions relate to Saint-Venant's principle for an incompressible elastic cylinder and more generally to the Phragmen-Lindelof principle and Liouville's theorem. Other contributions to the literature are briefly noted.