ACTUATORS, TRANSDUCERS AND MOTORS BASED ON GIANT MAGNETOSTRICTIVE MATERIALS

Rare earth-iron magnetostrictive alloys, especially Terfenol-D, featur e ''giant'' magnetostrains: static strains of 1000-2000 ppm and dynami c strains of 3500 ppm are reported. These strains permit building vari ous actuating devices (actuators, transducers, motors) both at macro a nd micro scale. The object of the paper is to recall adapted design me thods, especially finite element methods such as ATILA, and to review these different kinds of devices studied at Cedrat Recherche, providin g both up-dated experimental and numerical results. The presented devi ces will include several large displacement longitudinal and shear act uators biased using permanent magnets and used either as characterisat ion devices or as electromechanical actuators (for active damping, for sonar transducers...), a 1 kHz 4 kW Tonpilz-type sonar transducer cal led the Tripode, a 2 N m torque rotating Multi-Mode Motor, a torsion b ased drift free micro actuator and a wireless linear micromotor. (C) 1 997 Elsevier Science S.A.