NEHRP Clearinghouse

Title
Experimental and Analytical Study of a Hybrid Isolation System Using Friction Controllable Sliding Bearings.
File
PB93150282.pdf
Author(s)
Feng, M. Q.; Shinozuka, M.; Fujii, S.
Source
National Science Foundation, Washington, DC.; New York State Science and Technology Foundation, Albany., May 15, 1992, 101 p.
Identifying Number(s)
NCEER-92-0009
Abstract
The study deals with a hybrid sliding isolation system (HBIS) using friction controllable sliding bearings. The system controls the friction force on the sliding interface between the supported structure and the ground, by adjusting the pressure in a bearing chamber, to confine the sliding displacement within an acceptable range, while keeping the transfer of seismic force to a minimum. Instantaneous optimal control and bang-bang control algorithms are developed for controlling the friction force. The effectiveness of the algorithms is demonstrated by shaking table experiments and computer simulation. An HBIS using friction controllable bearings is fabricated and shaking table experiments are performed using a rigid structural model equipped with such a hybrid system. The dynamic chracteristics of the control system for bearing pressure and sliding friction are identified, and the advantage of the HBIS over the passive system is demonstrated by experiments. Computer codes for simulation of structural response under passive or hybrid control are developed. The numerically simulated results show good agreement with the experimental results, verifying that the analytical model developed represents the actual system very well.
Keywords
Earthquake resistant structures; Sliding friction; Friction controllable sliding bearings; Structural vibration; Bearing capacity; Algorithms; Mathematical models; Controllers; Control theory; Dynamic response; Buildings; Earthquake engineering; Vibration damping; Vibration isolators; Signal processing; Hybrid isolation system; Friction factor