A vibration isolator based on magneto-rheological elastomer

The paper presents an investigation about a magneto-rheological elastomeric (MRE) pad to be adopted as seismic semi-active isolator for lightweight structures. MRE pad may change its stiffness if immersed in a magnetic field. This characteristic allows to real time shift the fundamental frequency of the isolated structure. In this way it is possible to drive away the structure fundamental frequency from the exciting frequencies and therefore to reduce accelerations induced by the ground motion. The isolator includes a ball transfer unit (BTU) to sustain the vertical load so that MRE pad must only exert horizontal restoring forces and it may have a slender geometry without concern regarding bucklin