The frequency, amplitude and magnetic field dependent torsional stiffness of a magneto-sensitive rubber bushing

A dynamic torsional stiffness model of a magneto-sensitive circular annular rubber bushing is presented where influences of frequency, amplitude and magnetic field dependence are included. This is achieved by employing a newly developed non-linear magneto-sensitive audio frequency constitutive equation in an engineering formula for the torsional stiffness of a rubber bushing. The engineering stiffness formula predicts the frequency and amplitude dependent stiffness in a simple way, based on geometric dimensions and the shear modulus. The shear modulus is provided by the rubber model. The results from these calculations predict and clearly display the possibility of controlling the magneto-sensitive rubber bushing stiffness over a large frequency range, through the application of a magnetic field. (C) 2012 Elsevier Ltd. All rights reserved.