This paper describes a feasibility study on a high-damping device (HiDAM) installed in a building structure by way of a bracing mechanism.
A seismic response analysis with respect to a high-rise building approximately 100 m high is reported. Proper adjustment of the damping coefficient of the HiDAM (oil damper) provided an over all damping factor of about 10-20 per cent to the building structure, and reductions in the response, deformation and shear forces were verified analytically.
This paper reports also the performance confirmation tests conducted on a model device of the HiDAM which satisfied the specifications determined from the analytical results. The test results demonstrate the feasibility of the HiDAM and the possibility of utilizing it in high-rise buildings.
1. Introduction
Research and development of seismic response controlled structures began with a study by Kobori et al. published in 1950.' This work has been vigorously promoted in various areas in recent years, prompted by a proposal' for active seismic response control systems utilizing the latest computer and peripheral technologies. Research is under way at the same time to develop passive seismic response control systems with simpler, maintenance-free mechanisms that can reduce the seismic responses of structures with relative ease at low cost.
Various types of dampers3 intended to consume vibration energy are installed in passive seismic response controlled structures to reduce seismic response. They are installed via seismic elements such as braces in column-beam frames and may be hysteresis dampers or viscous (elastic) dampers. Elastoplastic dampers and friction dampers are both hysteresis dampers. Elastoplastic dampers4-utilize the energy consumed during elastoplastic deformation. Friction dampers 6s ' exploit the friction resistance between steel members. Viscous dampers and visco-elastic dampers are classified as viscous (elastic) dampers. Viscous dampers* utilize viscous resistance, which operates as a function of velocity. Visco-elastic dampers'. l o exploit the shear deformation of materials such as acrylic resin. Some of these dampers have already been used in the construction of high-rise buildings and other special structures. Elastoplastic dampers have been used in a large number of cases because of their stability under various conditions of use, but they are ineffective at *Senior Research Engineer ' Professor Emeritus of Kyoto University, Dr. of Eng. Chief Executive Adviser, Kajima Corporation *Principal Research Engineer t t Research Engineer **Senior Research Engineer