We study the localised buckling of an extensible conducting rod subjected to
end loads and placed in a uniform magnetic field. The trivial straight but
twisted rod is described by a fixed point of a four-dimensional Hamiltonian
system of equations previously shown to be chaotic. Localised solutions are
given by homoclinic orbits to this fixed point and we explore the spatial
complexity of localised rod configurations by means of shooting and parameter
continuation methods that exploit the reversibility of the system of
equations. Unlike in localisation studies of non-magnetic rods we find that
for certain parameter values multiple Hamiltonian-Hopf bifurcations occur.
Where these collide as parameters are varied, solutions exhibit
delocalisation-relocalisation behaviour. Our results predict buckling
instabilities and post-buckling behaviour of rods under combined mechanical
and magnetic loads, which is relevant for electrodynamic space tethers and
potentially for conducting nanowires in future electromechanical devices.
keywords: extensible elastic rod, Lorentz force, magnetic buckling, Hamiltonian-Hopf bifurcation, homoclinic orbits, spatial localisationPhysica D 284, 42-52 (2014)