NONLINEAR DYNAMIC CHARACTERISTICS OF MAGNETIC SHAPE MEMORY ALLOY ACTUATOR

摘要

A kind of hysteretic nonlinear model of magnetic shape memory alloy (MSMA) is developed in this paper, and the nonlinear dynamic characteristics of a MSMA actuator are studied. Nonlinear differential items are introduced to explain the hysteretic phenomena of MSMA, and the magneto-mechanical coupled model of MSMA actuator in harmonic magnetic fields is developed. The relationship between input magnetic signal and output displacement is obtained, and the phenomena of the MSMA actuator's accuracy aggravation in high-frequency magnetic field are explained. The theoretical and experimental results show that there are multiple frequencies in the response of the system, and the system's motions change from periodic orbits to chaos with the increase in the level of the input magnetic signals; the multi-frequency vibration is induced by the hysteretic nonlinear characteristics of magnetic shape memory alloy.