ABSTRACT Reliable operation of high‐performance magnetostrictive devices, composed of the giant magnetostrictive material (GMM), that is, the TbDyFe alloy, critically depends on an optimally tailored bias magnetic field. Sufficient intensity and uniformity are essential to induce the ideal initial strain in the GMM, enabling peak reciprocating output. This study develops a novel bias field scheme featuring the permanent magnet (PM)/pure iron (PI)/GMM stack assembly with dedicated thin cylindrical compensating PMs. This design first applies the principle of magnetic refraction to homogenize the magnetic field. By virtue of the refraction of the embedded PI layer at the PM/GMM interface, the magnetic field inhomogeneity within the GMM is reduced by 9%. Furthermore, a streamlined magnetic circuit model—derived from the concept of zero magnetomotive force (MMF)—provides robust support for the comprehensive magnetic leakage analysis. Finally, a large‐sized giant magnetostrictive actuator (GMA) with the proposed optimized configuration was fabricated and analyzed. Results demonstrate that this design ultimately reduces magnetic field inhomogeneity from 26.7% to 1.5% while increasing the average magnetic field intensity from 54 to 67 kA m −1 , and it can be extended to form devices with a large aspect ratio. This study facilitates the development of high‐precision and large‐output magnetostrictive devices. Additionally, it provides a generalized design paradigm for magnetic circuit structures in the development of high‐performance magnetic devices.
Yu et al. (Sun,) studied this question.