Equilibrium kink-like torsion deformation of a magnetoactive elastomer under a magnetic field

TL;DR

This paper predicts and confirms a new stable kink-like torsion deformation in magnetoactive elastomer beams under magnetic fields, revealing a transition boundary with unique magnetic and elastic properties.

Contribution

It introduces the first theoretical prediction and experimental validation of a kink-like torsion deformation in MAEs caused by magnetic fields, highlighting the deformation's magnetic and elastic characteristics.

Findings

Kink acts as a boundary between two magnetic states.

Magnetization in the kink region is non-collinear with the magnetic field.

Outside the kink, the beam is uniformly magnetized and undeformed.

Abstract

A novel effect involving the formation of a stable kink-like torsion deformation in a magnetoactive elastomer (MAE) beam subjected to a uniform magnetic field is theoretically predicted and experimentally confirmed. The phenomenon was demonstrated using an elastomer beam containing soft magnetic carbonyl iron microparticles within a silicone matrix. The torsion kink acts as a transition boundary between two undeformed homogeneous states of the beam. We show that the elastic moment is compensated by a magnetoelastic moment in the kink region, where the local magnetization of the beam is non-collinear to the applied magnetic field due to shape anisotropy. We It is established that within the kink region, the MAE beam exists in a non-uniformly elastically deformed, low-symmetry magnetic state. Outside the kink, the beam's magnetization is collinear with the magnetic field, corresponding to an undeformed, high-symmetry homogeneous magnetic state.