Static structures (e.g. – buildings) – Means compensating earth-transmitted force
Patent
1994-07-08
1996-02-20
Lindsey, Rodney M.
Static structures (e.g., buildings)
Means compensating earth-transmitted force
521673, E04H 902
Patent
active
054919380
DESCRIPTION:
BRIEF SUMMARY
BACKGROUND OF THE INVENTION
1. Field of the Invention
The field of invention comprises devices for damping vibrations of structures caused by seismic shock or the like.
2. Description of Related Art
A variety of active and passive seismic response control systems are known, including variable stiffness devices, to provide for the safety of structures. For instance, a variable stiffness earthquake-resisting mechanism may be integrated in a column-and-beam type frame structure in the form of an adjustable brace in which the rigidity of the variable stiffness mechanism, or the means of connection between the frame and the variable stiffness mechanism, functions to analyze seismic vibrational forces and to provide damping to offset these forces.
Prior art active seismic response control systems attempt to deal with seismic vibrations by actively shifting the natural frequency of the structure against the predominant period of a seismic vibration. However, seismic motion is an irregular vibration which does not have a clear predominant period, and in some instances, the predominant period is plural. Furthermore, in the case of prior art active seismic response control systems, various sensors as well as a controlling computer are used. To safeguard against the possibility of unforeseen events, a variety of safety maintenance mechanisms are necessary, the control of which becomes complicated. These safety mechanisms are not only costly, but require valuable start-up time to become effective. During this start-up period, the structure is either unprotected or not fully protected.
For instance, Kobori et al. U.S. Pat. No. 4,890,430 discloses an active damper which is computer controlled to vary the natural resonance of an entire building by actively varying the rigidity of selected structural members. Kobori. et al. U.S. Pat. No. 5,022,201 is an active seismic damper comprising a mass damper mounted on the top of a building. The damper is actively vibrated by an actuator connecting the mass to the building. Ishii et al. U.S. Pat. No. 5,025,599 discloses a combination active and passive damping device wherein a mass damper is rendered actively vibratable by a hydraulic actuator. In the event of a power failure, the device is converted to a passive damper wherein the mass is passively vibratable by coiled springs between the mass and the building which are excited solely by the energy of seismic vibration.
SUMMARY OF THE INVENTION
As used in this specification, the following definitions shall apply:
1. Active damper shall mean a seismic vibration damping device which, in order to function, requires an actuator energized by means other than the energy of seismic vibration.
2. Passive damper shall mean a seismic damping device which functions without an actuator and is energized solely by the energy of seismic vibration.
3. Actuator shall mean a mechanical, electro-mechanical, electrical, and/or electronic means for energizing an active damper.
4. Control force shall mean the force applied by a seismic vibration damping device to a structure to damp seismic vibrations in the structure.
5. Fail safe means shall mean a device to automatically deactivate a seismic vibration damper to protect the damper from damage due to overload or malfunction.
6. Column and beam shall mean state of the art construction materials used to form the vertical and horizontal frame portions of a structure.
The basic concept of the invention is to use a rigid frame structure with a stiffness factor of approximately one-half of the stiffness and strength factor of a frame required in a normal design. To compensate for the reduced rigidity of the frame structure, the damping devices, in combination with earthquake-resisting elements, such as braces, are secured to the column-and-beam frame of the structure. Maximum damping capacity is obtained for the structure, and the response of the structure is minimized by preliminarily setting the damping coefficient of the inventive high damping device at a proper value. Although a structure having on
REFERENCES:
patent: 3538653 (1970-11-01), Meckler
patent: 3796017 (1974-03-01), Meckler
patent: 4318768 (1988-12-01), Cardan
patent: 4799339 (1989-01-01), Kobori et al.
patent: 4890430 (1990-01-01), Kobori et al.
patent: 4901486 (1990-02-01), Kobori et al.
patent: 4922667 (1990-05-01), Kobori et al.
patent: 4959934 (1990-10-01), Yamada et al.
patent: 4964246 (1990-10-01), Kobori et al.
patent: 5022201 (1991-06-01), Kobori et al.
patent: 5025599 (1991-06-01), Ishii et al.
patent: 5036633 (1991-08-01), Kobori et al.
patent: 5046290 (1991-09-01), Ishit et al.
patent: 5065552 (1991-11-01), Kobori et al.
patent: 5097547 (1992-03-01), Tanaka et al.
patent: 5107634 (1992-04-01), Onoda et al.
patent: 5147018 (1992-09-01), Kobori et al.
patent: 5271197 (1993-12-01), Uno et al.
patent: 5339580 (1994-08-01), Koshika et al.
patent: 5347771 (1994-09-01), Kobori et al.
Hatada Tomohiko
Ishida Masatoshi
Kobori Takuji
Kurata Narito
Mizuno Takayuki
Kajima Corporation
Lindsey Rodney M.
Tilberry James H.
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