关键词: 磁致伸缩作动器, ΔE效应, 动力学模型, 参数振动, 摄动法

Abstract:

Elastic modulus E of giant magnetostrictive materials changes with themagnetic field and the stress, which is known as the ΔE effect. This paper proposes a dynamic model of magnetostrictive actuator that takes into consideration the ΔE effect. The feature of the model is the existence of both parametric excitation and external excitation, which is different from ordinary parametric vibration or forced vibration. The perturbation method is applied to solve and analyze the model. The spectrum charateristics and resonance frequency of parameter vibration are obtained. The danger of such structures under excitation of sub-harmonic resonance is analyzed by means of stability analysis in combination with an analysis based on the stability theorem considering external excitation. The amplitude of sub-harmonic resonance is considered when the frequency of the driving current is equal to 1/2 inherent frequency of the actuator. The conclusions obtained can be used as reference in the design of giant magnetostrictive actuators and smart structures with magnetostrictive materials.

Key words: magnetostrictive actuator, ΔE effect, dynamic models, parameter vibration, perturbatio method