A 2D dynamic formulation for nonlinear finite element modelling of Terfenol-D rods

This paper deals with the new giant magnetostrictive materials that have become available during the past years. They are based on alloys of rare earth element and iron, where the most common alloy, named Terfenol-D, has the composition Tb_0.27-0.3 Dy_0.73-0.7 Fe_1.9-2.0. These type of materials offer new possibilities for the development of new devices with high energy density, fast response and ultra-fine precision. So far these new materials have been used in such diverse applications as underwater sound transducers, linear and rotary motors, active vibration control, actuators, etc. The paper reports the development of a method for the design and analysis of devices based on giant magnetostrictive materials. A model for the simulation of the dynamic behaviour of the nonlinear magneto-elastic medium is presented. The coupled magnetic, magnetoelastic and mechanical equations that describe the magnetostrictive problem are solved by means of the finite element method. The nonlinear properties of the giant magnetostrictive materials, obtained from static material characterizations, are used as the numerical input to the simulation model by means of the thin sheets bending principle