Three-Dimensional Device Using Bilinear Spring Mechanism and Ball Screw

Abstract

In this paper, a vertical seismic isolation device using bilinear spring mechanism and a ball screw type damper was made in order to obtain a vertical isolation device having large effect of seismic isolation and less static deflection. Three-dimensional seismic isolation device consisting of the vertical seismic isolation device and the horizontal seismic isolation device was made and the effects seismic of isolation were substantiated experimentally and numerically. The experimental and calculated results showed that the vertical isolation device has the natural frequency of 0.54 Hz and the static deflection of 100 mm. The maximum horizontal and vertical response acceleration decreased to about 1/7 and 1/2 respectively compared with the maximum input accelerations.