On the influence of loading force on the vibration characteristics of a giant magnetostrictive transducer

Abstract

The vibration characteristics of a giant magnetostrictive transducer play a significant role in the stability and processing effect of spinning ultrasonic machining. The output characterization of the giant magnetostrictive transducer is unstable subject to an powerful external load, which severely restricts the application of giant magnetostrictive transducer in industry. In this study, the effect of change of load force and electrical parameter in the different directions on the high-frequency (about 20 kHz) vibration output characteristics of the giant magnetostrictive transducer is investigated, through finite element analysis and static loading experimental. The result shows that the electrical parameter of a giant magnetostrictive transducer has a similar changing trend with the increasing of the axis and radial force load; The resonant frequency also increases with the increase of electrical parameter and load force; The amplitude attenuation of ultrasonic vibration will become extraordinary intense even almost to stop beat when the axis force load increase to 750 N and radial force load increase to 550 N; The gradient of resonant frequency in a radial direction is more significant than that in an axial direction. Based on the results of theoretical analysis and static loading experimental, the measures to reduce amplitude attenuation and improve output stability of amplitude under resonant frequency are proposed. The results can provide theoretical guidance for a magnetostrictive transducer used in the actual spinning ultrasonic vibration processings.