Application of the Villari effect to electric power harvesting

Abstract

Transducers utilizing the Villari effect (inverse-magnetostrictive effect) consist of a coil wound on a core of magnetostrictive material. In this paper, a linear magnetomechanical coupling model is developed to analytically calculate the potential electrical power such transducers can generate when subjected to applied harmonic mechanical vibration. Two vibration modes, force driven and displacement driven, are distinguished. The eddy current effect in the magnetostrictive core material and the leakage inductance of the coil are taken into account. Comparisons of output electrical power are presented for Terfenol-D and Galfenol magnetostrictive cores.

Magnetomechanical performance of directionally solidified Fe–Ga alloys

“…However, Galfenol has a very high magnetic permeability relative to Terfenol, and this makes the eddy current effect much more significant when the magnetization is changed either by external fields or by applied stresses and measures such as lamination would have to be chosen to reduce this effect. 2 …”

“…1,2 However, the intrinsic brittleness of Terfenol-D, especially under tensile stresses, puts certain limitations on the design for all types of applications.…”

Magnetoelastic Energy Harvesting: Modeling and Experiments

“…Another topic in the analysis of a harvester, based on magnetoelastic materials, is the eddy currents effect due to the mechanical stress variations, that can have a detrimental effect on the harvester performances [51]. This phenomenon is present when the material has a finite electric resistivity, that is the case of magnetostrictive materials as Terfenol and Galfenol.…”

“…Recently, they have received a lot of interest for actuating and sensing purposes. Moreover, in the general framework of recovering some environmental energy, this kind of smart materials have been considered to recover the mechanical energy of vibrations [51].…”

Recent Results on the Brittle Fracture of Terfenol-D Specimens under Magnetic Field

“…High power ultrasonic transducers make a large use of it, as well as automotive industry, avionics and robotics, which commonly use robust and responsive actuators and sensors based on the phenomenon of magnetostriction (Calkins et al, 2007). Terfenol-D has recently been used to produce sensors designed for stress monitoring of steel cables in suspended bridges (Zhang et al, 2014) and it might be employed in energy harvesting devices (Zhao and Lord, 2006;Li et al, 2010;Mori et al, 2015).…”