Performance of a low-frequency hybrid vibration isolation platform for vibration-sensitive devices

For preventing the fragile optical communication devices from malfunction caused by the low-frequency seismic excitation, a novel three-dimensional hybrid isolation platform is proposed in this paper. To isolate the horizontal and vertical vibrations simultaneously, the platform is designed as a combination of a rolling isolation system and four three-parameter isolators with active damping. By deriving the governing equations of the three-parameter isolators and the profile of the concave rolling surface, the dynamic model of the whole platform is constructed. Numerical results indicate that the isolation platform has an effective suppression of the horizontal and vertical vibrations. To verify the isolation performance of the hybrid isolation platform, an experiment is conducted in the targeting frequency range. Compared to the amplification factor of 6.2 dB of the three-parameter isolator, the test results exhibit that the hybrid isolation shows no amplification effect in the vertical direction, and the root mean square value of acceleration responses can be decreased by more than 65% in the frequency range of 0–32 Hz. In the horizontal direction, the reduction of the root mean square value of acceleration responses is up to 85% in the same frequency range.