Modeling of output characteristics of giant magnetostrictive transducer considering temperature and eddy currents

Abstract

Due to the high conductivity and low permeability of giant magnetostrictive materials (GMMs), eddy currents and temperature rise caused by these materials are unavoidable. These factors will significantly impact the output efficiency and reliability of giant magnetostrictive transducers (GMTs). It is essential to conduct precise evaluations of the output characteristics in various temperature settings to effectively design and optimize the transducer. However, to reduce the eddy current loss of GMMs, a radial slit is introduced. The intricate geometry also contributes to the complexity of analysis. According to the practical engineering requirements, this paper initially established a testing system for GMM characteristic and analyzed the mechanism between material temperature and output characteristics. Second, improvements have been made to the equivalent circuit method. Research has been conducted on the influence of temperature and eddy currents on the electrical and mechanical equivalent circuits, leading to the creation of a comprehensive equivalent circuit model for GMTs. Finally, a testing platform has been set up to assess the temperature-output characteristics of the transducer. The impedance and displacement characteristics of a GMT were examined to validate the proposed model. The test results demonstrated that within the 20 – 100 °C range, the discrepancy between the model and the measured impedance is under 1%, and the displacement amplitude error is less than 5%, thus confirming the precision of the proposed model.