Abstract
This paper demonstrates the effectiveness of a passive vertical vibration isolation device proposed by the authors through experiments. The device is composed of a combination of constant-load springs, which sustain constant loads regardless of the magnitude of deformation. The use of constant-load springs as a restoring mechanism limits the transmission of the reaction force from the ground to the object placed on the device within a specified value. This way, the device can reduce the maximum response acceleration of the object to a specified value regardless of the kinds and magnitudes of earthquake ground motions. Moreover, the device can avoid resonance.
