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Time-varying output characteristics of high-power giant magnetostrictive actuators (GMA) are determined by magnetic-thermal-mechanical coupling field effect. However, the influence of non-uniform magnetic field and temperature distribution on the output displacement of GMA is often ignored in the present researches. Therefore, a comprehensive model under multi-physics effects is established in this paper. Firstly, the leakage flux and eddy current effects are taken into account, and the non-uniform magnetic circuit model (MCM) is built. Then, the uneven power losses of heat source in GMA are analyzed according to the MCM results. A three-dimensional time-domain thermal circuit is developed based on the heat transfer equation and the "T" equivalent thermal circuit model. Finally, the time-varying displacement is calculated on the basis of multi-degree-of-freedom dynamics theory, so as to build the entire model. Compared with the traditional lumped parameter model and the steady-state thermal field researches, the proposed model is more accurate in analyzing temperature distribution and output characteristics of GMA under different working conditions. Furthermore, the proposed model can also provide a guidance for the temperature management methods and the optimal designing scheme of GMA in various application scenarios. The accuracy and effectiveness of the proposed model have been verified by experiments. [Display omitted] • A magneto-thermo-mechanical coupling model considering non-uniform flux distribution is built in this paper. • The multi-temperature node thermal circuit could calculate time-varying characteristics of GMA accurately. • Compared with existing literatures, this paper focuses on the time-varying output of the GMA due to temperature rise. • The magnetic field distribution is uneven in GMM, thus affecting the temperature and output characteristics of GMA. • As the temperature increases, the output displacement of the transducer decreases, by more than half at most. [ABSTRACT FROM AUTHOR]

The paper presents the numerical and experimental investigations of the axisymmetric magnetostrictive actuator with a Terfenol-D rod. The applied model consists of equations that describe the magnetic and mechanical displacement fields. The equations of both fields are coupled through a nonlinear magneto-mechanical constitutive law. The model is considered as 2D axisymmetric. The finite element method is used to solve the field equations. Special attention is paid to the proper definition of magneto-mechanical relations. These relations are formed from measurements. A unique test stand is designed for the experimental investigation. The selected results of the simulation are compared with the measurement results. The comparison shows that the applied numerical model is sufficiently accurate.

The paper presents the numerical and experimental investigations of the axisymmetric magnetostrictive actuator with a Terfenol-D rod. The applied model consists of equations that describe the magnetic and mechanical displacement fields. The equations of both fields are coupled through a nonlinear magneto-mechanical constitutive law. The model is considered as 2D axisymmetric. The finite element method is used to solve the field equations. Special attention is paid to the proper definition of magneto-mechanical relations. These relations are formed from measurements. A unique test stand is designed for the experimental investigation. The selected results of the simulation are compared with the measurement results. The comparison shows that the applied numerical model is sufficiently accurate. [ABSTRACT FROM AUTHOR]