A low frequency magnetostrictive inertial actuator for vibration control

Magnetostrictive inertial actuators are profitably used in applications of vibration control. However their use is limited to high frequencies because of problems related to control stability and to small exertable forces. This paper presents the design of an innovative low-frequency magnetostrictive inertial actuator. With respect to traditional magnetostrictive actuators it is able to significantly multiply the amplitude of the elongation of the magnetostrictive bar and to extend its functioning well below the working frequencies of traditional devices. The design of the actuator has been optimized through both an analytical model and a finite element model taking into account all the design parameters. The optimized low-frequency magnetostrictive inertial actuator has then been produced and its frequency response compared to that of a traditional magnetostrictive actuator made up of the same components (except for the supporting structure).