scholarly journals AN EXPERIMENTAL STUDY ON THE RESTORING FORCE CHARACTERISTICS OF THE FRICTION DAMPER WITH CONED DISC SPRINGS FOR BASE-ISOLATION SYSTEM

1998 ◽  
Vol 63 (510) ◽  
pp. 75-82 ◽  
Author(s):  
Takashi NAKAMURA ◽  
Tetsuo SUZUKI ◽  
Satoru INABA
Keyword(s):  
Experimental Study ◽  
Base Isolation ◽  
Friction Damper ◽  
Restoring Force ◽  
Isolation System ◽  
Base Isolation System ◽  
Force Characteristics

Reduction of Seismic Response of Mechanical System by Base Isolation System With Friction Bearing

2007 ◽  
Author(s):  
Shigeru Aoki ◽  
Yuji Nakanishi ◽  
Kazutoshi Tominaga ◽  
Takeshi Otaka ◽  
Tadashi Nishimura ◽  
...  
Keyword(s):  
Mechanical System ◽  
Seismic Response ◽  
Base Isolation ◽  
Low Frequency ◽  
Simulation Method ◽  
Shaking Table ◽  
Restoring Force ◽  
Isolation System ◽  
Friction Bearing ◽  
Base Isolation System

Reduction of seismic response of mechanical system is important problem for aseismic design. Some types of base isolation systems are developed and used in actual base of buildings and floors in buildings for reduction of seismic response of mechanincal system. In this paper, a base isolation system utilizing bearing with friction and restoring force of bearing is proposed. Friction bearing consists of two plates having spherical concaves and oval type metal or spherical metal with rubber. First, effectiveness of the base isolation system is examined experimentally. Using artificial time histories, the isolated table is shaken on the shaking table. The maximum value of response is reduced and sum of squares of response is significantly reduced. Power spectrum is significantly reduced in almost of all frequency regions, except for very low frequency region. Next, in order to examine reduction of seismic response of actual mechanical system, a console rack is set on the isolated plate. Seismic response is also significantly reduced. Finally, obtained results of experiment are examined by simulation method. An analytical model considering friction and restoring force is used. From simulation method, effectiveness of the proposed base isolation system is demonstrated.

scholarly journals EXPERIMENTAL STUDY ON THE BASE ISOLATION SYSTEM

1986 ◽  
Vol 362 (0) ◽  
pp. 54-65
Author(s):  
HIDEYUKI TADA ◽  
AKIRA SAKAI ◽  
MINEO TAKAYAMA
Keyword(s):  
Experimental Study ◽  
Base Isolation ◽  
Isolation System ◽  
Base Isolation System

scholarly journals Pilot Study for Investigating the Cyclic Response of the Recentering Bridge Bearing System Combined with the Friction Damper

2016 ◽  
Vol 2016 ◽  
pp. 1-17
Author(s):  
Jong Wan Hu ◽  
Yong-il Cho
Keyword(s):  
Energy Dissipation ◽  
Base Isolation ◽  
Permanent Deformation ◽  
Residual Deformation ◽  
Friction Damper ◽  
Isolation System ◽  
Cyclic Loading Condition ◽  
Base Isolation System ◽  
Bridge Bearing ◽  
Bearing System

The bridge bearing is one of the component members which provide resting supports between piers and decks. The bridge bearing is intended to control longitudinal movement caused by traffic flow and thermal expansion, thereby reducing stress concentration. In high seismicity area, the bridge bearing has been utilized as the base isolation system to mitigate acceleration transferred from the ground. Although the existing bridge bearing installed between superstructure and substructure provides extra flexibility to the base of the entire structure, considerable permanent deformation occurs due to lack of recentering capacity after earthquake. It is required to spend extra cost for repairing impaired parts. The bridge bearings integrated with superelastic shape memory alloy (SMA) devices used for upgrading the recentering effect into the friction damper are proposed in this study. The refined finite element (FE) analyses are introduced to reproduce the response of such new structures under cyclic loading condition. The bridge bearing systems that maintain uniform recentering capability are designed with various friction coefficients so as to examine energy dissipation and residual deformation through FE analyses. After observing FE analysis results, optimal design for the recentering bridge bearing system will be proposed to take advantage of energy dissipation and self-centering capacity.

A Smart Base-Isolation Using Piezoelectric Friction Damper

2011 ◽  
Vol 250-253 ◽  
pp. 1281-1286 ◽  
Author(s):  
Na Xin Dai ◽  
Ping Tan ◽  
Fu Lin Zhou
Keyword(s):  
Dynamic Response ◽  
Control Strategy ◽  
Base Isolation ◽  
Friction Damper ◽  
Isolation System ◽  
High Efficient ◽  
Base Isolation System ◽  
External Power ◽  
Rubber Bearings ◽  
Smart Base Isolation

A smart base-isolation system, composed of low damping bearings and piezoelectric friction damper is studied in this paper. The semi-active piezoelectric friction damper (PFD[1]) is proposed for control of peak dynamic response of seismic-excited structures. In the proposed PFD device, the friction force between two sliding plates is regulated by controlling the normal force using piezoelectricity across the damper, and its advantage is that its operation requires only minimal external power. A high efficient control algorithm is proposed for the semi-active control of the friction damper using a simple static output. The effectiveness of the PFD device and the control strategy in reducing the peak dynamic response of structures is investigated through an application to a 5-story base-isolated building. Numerical results demonstrate that the proposed PFD device and the control strategy are effective in reducing the peak drift of rubber-bearings of the base-isolated building subject to earthquakes.

scholarly journals Influence of Elastomeric Bearings in Tension on the Seismic Performance of Base-Isolated r.c. Buildings

2020 ◽  
Vol 11 (1) ◽  
pp. 82
Author(s):  
Fabio Mazza ◽  
Mirko Mazza
Keyword(s):  
Base Isolation ◽  
Nonlinear Models ◽  
Vertical Component ◽  
Computer Code ◽  
Nonlinear Phenomena ◽  
Isolation System ◽  
Elastomeric Bearings ◽  
Near Fault ◽  
Base Isolation System ◽  
Near Fault Earthquakes

Elastomeric bearings are commonly used in base-isolation systems to protect the structures from earthquake damages. Their design is usually developed by using nonlinear models where only the effects of shear and compressive loads are considered, but uncertainties still remain about consequences of the tensile loads produced by severe earthquakes like the near-fault ones. The present work aims to highlight the relapses of tension on the response of bearings and superstructure. To this end, three-, seven- and ten-storey r.c. framed buildings are designed in line with the current Italian seismic code, with a base-isolation system constituted of High-Damping-Rubber Bearings (HDRBs) designed for three values of the ratio between the vertical and horizontal stiffnesses. Experimental and analytical results available in literature are used to propose a unified nonlinear model of the HDRBs, including cavitation and post-cavitation of the elastomer. Nonlinear incremental dynamic analyses of the test structures are carried out using a homemade computer code, where other models of HDRBs considering only some nonlinear phenomena are implemented. Near-fault earthquakes with comparable horizontal and vertical components, prevailing horizontal component and prevailing vertical component are considered as seismic input. Numerical results highlight that a precautionary estimation of response parameters of the HDRBs is attained referring to the proposed model, while its effects on the nonlinear response of the superstructure are less conservative.

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