The Effects of Local Modes on Vibration Reduction of Building Isolation

This paper investigates the vibration isolation performance of isolated box structures. Isolated box inside building is a one of the building isolation designs. Some experimental methods are developed to analyze the effects of bending mode of the box structure on vibration isolation efficiency. The vibration reduction performance of an isolated box inside building is found to be degraded by bending resonances of the isolated box. In the design of building isolation, apart from the conventional design of natural frequency of rigid body vibration, the control of local mode resonance frequencies is found to be also important.