Controllability of the elastic modulus and stiffness of magnetostrictive material spring element in a mechanical vibration system

Different from common materials, elastic modulus of magnetostrictive materials (MsM) can undergo changes during working in the process of magnetostrictive positive effect driving. The spring element with wider stiffness coefficient range can developed according to the changing characteristics of MsM's elastic modulus. In this paper, we established a mathematical description for the changeable elastic modulus of MsM during the application of magnetic or stress field. We propose to use an MsM transducer as the spring element of the free vibration mechanical system to make its stiffness adjustable so as to achieve active vibration control. After proposing voltage control method to adjust stiffness, we study the criteria on various conditions during stiffness adjustment. We also study the effect of material shape, coil parameters, and other factors on the speed of stiffness adjustment. We find that stiffness adjustment time increases with the length of MsM as well as the diameter of the coil. The research results are beneficial to understand the process of applying MsM to actively control system vibration.