Modelling of worm-like motion systems with magneto-elastic elements

Observing the locomotion of worms, one recognizes a conversion of (mostly periodic) internally driven motions into change of external position (undulatory locomotion). In this paper we consider the motion of a system of two material points, connected by a spring made of magnetisable elastic material. By the influence of a magnetic field the spring extends in the direction orthogonal to the field. Through an harmonic change of the field a small lengthening internal force appears. We investigate the system in vicinity of the main resonance. It is shown that through the presence of a non-symmetric Coulomb dry friction a motion of the system with a constant "on the average" velocity is possible and stable. We obtain the expression for velocity. (C) 2004 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim