Shell mechanisms are patterned surface-like structures with compliant
deformation modes that allow them to change shape drastically. Examples include
many origami and kirigami tessellations as well as other periodic truss
mechanisms. The deployment paths of a shell mechanism are greatly constrained
by the inextensibility of the constitutive material locally, and by the
compatibility requirements of surface geometry globally. With notable
exceptions (e.g., Miura-ori), the deployment of a shell mechanism often couples
in-plane stretching and out-of-plane bending. Here, we investigate the
repercussions of this kinematic coupling in the presence of geometric
confinement, specifically in tubular states. We demonstrate that the
confinement in the hoop direction leads to a frustration that propagates
axially as if by buckling. We fully characterize this phenomenon in terms of
amplitude, wavelength, and mode shape, in the asymptotic regime where the size
of the unit cell of the mechanism~r is small compared to the typical radius
of curvature~ρ. In particular, we conclude that the amplitude and
wavelength of the frustration are of order r/ρ and that the mode
shape is an elastica solution. Derivations are carried out for a particular
pyramidal truss mechanism. Findings are supported by numerical solutions of the
exact kinematics.Comment: 7 figures, added figures and references, corrected typo