Nonlinear 2-D transient modeling of Terfenol-D rods

A nonlinear model for simulation of the transient behavior of magnetostrictive Terfenol-D rods has been developed. The model is based on static characterization of the magnetic and mechanical properties of the rods combined with Maxwell´s equations and classical mechanic laws. Registrations for different rods are stored in a database which is called upon by the model. The model is able to handle longitudinal wave propagation and eddy current influence under transient conditions. Any combination from the set of magnetic field (current), magnetic flux density (voltage), mechanical motion, mechanical stress, and mechanical impedance can be used as the two independent variables in the model. This modeling technique implies that the experimental set-up used for data acquisition of the material properties should be regarded as a part of the modeling process. The experimental set-up used for the characterization of Terfenol-D properties can produce magnetic fields and mechanical stresses independently of each other and of arbitrary shape. A specially designed sample holder provides a homogeneous magnetic field and mechanical stress field inside the rod