Design and analysis of a nested structure micro-displacement amplification mechanism for a galfenol-based actuator

Abstract

In this paper, two galfenol rods are arranged in a nested structure to amplify the micro-displacement of an actuator. First, a finite element model of the actuator is developed to analyze the magnetization process of the actuator for different material of the sleeves. Secondly, the mathematical model of the actuator is established using the theory of magnetization, magnetostriction, and structural dynamics to describe the output displacement characteristics of the actuator at different frequencies; the hysteretic behavior of the actuator is taken into consideration and is modeled according to Jiles–Atherton hysteresis model. The experiments and results show that the output displacement of the dual galfenol rods-based actuator is significantly larger than that of a single galfenol rod-based actuator under the same experimental conditions, in addition to that, the proposed nested structure exhibits the advantages of occupying small volume and maintaining response dynamics even at high frequencies. Finally, using the established mathematical model, studies are carried out to analyze the feasibility of further amplification of the output displacement using more than two galfenol rods in a nested structure.