Examination of Performance of Oil Damper for Houses Connecting Foundation and Ceiling with Oscillator (Effectiveness of Various Shapes of Oscillator)

Abstract

Reduction of seismic response of houses is important for protection from destruction of houses. Some types of dampers have been developed in order to add the damping force to houses. However, these dampers have disadvantage that the dampers are effective in only one horizontal direction. In this paper, various shapes of oil dampers for two story houses are proposed, and these dampers have damping effect toward 3 dimensional vibration. Shapes of the dampers are the rectangular solid damper, the cylindrical damper and the spherical damper. The oil dampers are fixed at foundation and connected to the ceiling of the first story using a connecting rod. First, using a two story house experimental model with dampers, resonance curves including the first and the second vibration modes of the first and the second stories are obtained. Comparing the resonance curves of the model without dampers, peaks of the resonance curves are suppressed for any shapes of the dampers. Next, the effectiveness of the dampers is examined by numerical simulation. The experimental model is modeled as a two-degree-of-freedom system. Using actual earthquake records as input, responses of the first and the second stories are calculated. The maximum responses and the root mean square value of the responses are reduced when any shapes of the dampers are used.