High-speed giant magnetostrictive actuator using laminated silicon steel core.

The high-frequency eddy current loss limits the output speed of the giant magnetostrictive actuator (GMA). This paper investigates a GMA using a laminated silicon steel core. Compared with the integral silicon steel core, the laminated silicon steel core can reduce the equivalent conductivity and eddy currents. The laminated structure reduces the magnetic reluctance of the core and increases the magnetic field intensity in the giant magnetostrictive material rod. Therefore, the actuator can output large vibration amplitude under high-frequency magnetic field. At the sinusoidal excitation current of 35 A (rms) @ 2 kHz, the output vibration amplitude of the actuator using the laminated silicon steel core is 11.1 µm @ 4 kHz, which is 44.2% higher than that of the actuator with the integral silicon steel core. This indicates that the laminated structure of the magnetic core is beneficial to improve the output speed of GMA.