A Study of Vibration Characteristics for Silosane Based MR Elastomers

초록

This paper presents stiffness characteristic of magnetorheological (MR) elastomer, whose elastic modulus is controllable by an applied magnetic field. MR elastomers consist of natural or synthetic rubber filled with micron-sized magnetizable particles. Therefore the stiffness can be changed variously according to the magnetic flux density. By using this property, the material can be applied to vibration absorber used in many parts of structures. However, the performance of MR elastomer on vibration reduction is various depending on different magnetically polarization direction and dimension during the manufacturing process. In this paper, in order to obtain the optimal characteristics of MR elastomer, a series tests using MR elastomers with different types and dimensions are prepared. The extent of natural frequency shifted against magnetic field at various excitation frequencies can be measured. MR elastomers were duplicated with siloxane polymer, iron, nickel and cobalt powder combination in mould, and cured. Specimens are prepared with 3 types which are unexposed and exposed to magnetic field vertically, horizontally during cure. Also, a set of design variables are considered to produce MR elastomers. Through the modal tests of mass structure with MR elastomer, the optimal design as well as the polarization direction of MR elastomer is obtained.