We show how an energy analysis can be used to derive the equilibrium
equation and boundary conditions for an end-loaded variable ply much more
efficiently than was done in previous works. Numerical results are then
presented for a clamped balanced ply approaching lock-up. We also use the
energy method to derive the equations for a more general ply made of
imperfect anisotropic rods and briefly consider their helical solutions.
keywords: loaded ply, variational calculus, clamped boundary conditions, anisotropic rod, helixJournal of Vibration and Control 9, 175-185 (2003)