We investigate axially symmetric localized bulging of an incompressible hyperelastic circular
solid cylinder or tube that is rotating about its axis of symmetry with angular velocity
. For such
a solid cylinder, the homogeneous primary deformation is completely determined by the axial
stretch
,
and it is shown that the bifurcation condition is simply given by
if the resultant
axial force
is fixed. For a tube that is shrink-fitted to a rigid circular cylindrical spindle, the azimuthal
stretch
on the
inner surface of the tube is specified and the deformation is again completely determined by the
axial stretch
although the deformation is now inhomogeneous. For this case it is shown that with
fixed the bifurcation
condition is also given by
.
When the spindle is absent (the case of unconstrained rotation), we also
allow for the possibility that the tube is additionally subjected to an internal
pressure . It is
shown that with
fixed, and
and
both viewed
as functions of
and
,
the bifurcation condition for localized bulging is that the Jacobian of
and
should vanish. Alternatively, the same bifurcation condition can be derived by fixing
and setting the
Jacobian of
and
to zero. Illustrative numerical results are presented using the Ogden and Gent
material models.