Design And Research Of Damper Based On Smart Material Excited By Magnetic Field

Both giant magnetostrictive materials (GMM) and magntorheological fuid (MRF) are smart materials which has the potential to be used in the vibration control and some other technology fields because of their inherent excellent properties. GMM and MRF are both excited by magnetic field which is generated by electric current or permanent magnet. Scientists all over the world focused much attention on the preparation and the mechanical properties of GMM and MRF, and the control strategies of the equipments which consist of the two materials. Several significant achievements have been obtained in these fields, however, few literatures details the analysis and the design methods of the magnetic circuit in GMM actuators or MRF dampers, which are the primary coverage of this paper. The main points are such as the following two parts:1. Design and research on GMM actuatorIn order to meet the requirement of large output force in vibration suppression of civil engineering structures, a high-power GMM actuator consists of Terfeno-D, which is a kind of alloy made from several rare earth-irons, has been fabricated. The static force and the displacement it can generate were more than 5.5 ton and 250μm, respectively. The detailed design method, especially about the permanent magnetic circuit, was given and the feasibility of the method was testified by Finite Elements Method (FEM) analysis with the usage of the commercial software Ansys. Besides, the key parameters such as the dimension of solenoid and the distance between the permanent magnets which affects the performance of GMM actuators greatly were studied. In the process of the above analysis some new phenomenon were found and explained. An elementary investigation of calorific characteristics of GMM actuators was also carried out.2. Design and research on MRF damperComprehensive FEM static magnetic analysis of MRF damper was performed. Many main structural parameters, which significantly influence the magnetic features of MRF dampers, such as the gap between the piston and the house of damper, the distance between the current-carrying coils etc., were studied. Then some effective new ways to optimize the magnetic circuit were introduced.