Dynamic Characteristics of a Sliding Bearing Using Lubricant Material for Base Isolation of Light Structures

2003 ◽  
Author(s):  
Nobuo Masaki ◽  
Sadamitsu Takeuchi ◽  
Hisashi Hirata

The authors have been developed a system for base isolation of a wooden house and a prefabricate house. It consists of sliding bearings and laminated rubber bearings. There are two types of sliding bearings, one has the coefficient of friction of 0.046, the other has 0.06. Each of sliding bearings supports 30 ∼ 40kN of vertical load, the surface pressure of the sliding shoe is 10 ∼ 12 N/mm2 (10∼12MPa). The horizontal stiffness of the laminated rubber bearing is 38.5N/mm. For base isolation of an ordinary wooden house, 12 ∼ 16 sliding bearings and 4 ∼ 6 laminated rubber bearings are used. If the mass of a wooden house is 40ton and it is supported by 16 sliding bearings of the coefficient of friction of 0.046 and attached by 4 laminated rubber bearings with the horizontal stiffness of 38.5 N/mm, therefore it has 0.249 of the equivalent damping factor and 3.2 second of the natural period. As for the base isolated houses which are used this system, 500 houses have been constructed in Japan currently by the August of 2002 (Takahashi, 2002). As an advanced system of this base isolation system, we have developed a new type of the base isolation system of sliding bearing using silicone lubrication materials and rubber spring devices.

2001 ◽  
Vol 7 (12) ◽  
pp. 99-104 ◽  
Author(s):  
Ichizo KAWABATA ◽  
Masaharu TAKAYAMA ◽  
Yasuhiro NISHIKAWA ◽  
Yuichi KIMURA ◽  
Eiichi YAMAZAKI ◽  
...  

2012 ◽  
Vol 594-597 ◽  
pp. 1788-1799 ◽  
Author(s):  
Donato Cancellara ◽  
Fabio de Angelis

In the present paper the dynamic nonlinear analysis for a 3D base isolated structure is illustrated. A base isolated reinforced concrete building is designed and verified according to the European seismic codes such that the superstructure remains almost completely elastic and the nonlinear elements are localized only in the base isolation system. Nonlinear hysteretic models have been adopted to reproduce the cyclic behavior of the isolators. Two different base isolation systems are considered and their performances are compared for evaluating the behaviour of a base isolated building, highly irregular in plan, in presence of a seismic excitation defined with recorded accelerograms which characterize the bi-directional ground motions. The isolation system has been realized with a combination in parallel of elastomeric bearings and sliding devices. In the first analyzed isolation system we have used the High Damping Rubber Bearings (HDRB) and in the second analyzed isolation system we have used the Lead Rubber Bearings (LRB). Finally a comparative analysis between the base isolated structure with hybrid base isolation systems and the conventional fixed base structure is detailed.


Author(s):  
Krzysztof Wilde ◽  
Paolo Gardoni ◽  
Yozo Fujino ◽  
Stefano Besseghini

Abstract Base isolation provides a very effective passive method of protecting the structure from the hazards of earthquakes. The proposed isolation system combines the laminated rubber bearing with the device made of shape memory alloy (SMA). The smart base isolation uses hysteretic behavior of SMA to increase the structural damping of the structure and utilizes the different responses of the SMA at different levels of strain to control the displacements of the base isolation system at various excitation levels. The performance of the smart base isolation is compared with the performance of isolation by laminated rubber bearings to assess the benefits of additional SMA damper for isolation of three story building.


2012 ◽  
Vol 2012 (0) ◽  
pp. _405-1_-_405-8_
Author(s):  
Shun SUMINOKURA ◽  
Katsumi KURITA ◽  
Shigeru AOKI ◽  
Yuji NAKANISHI ◽  
Kazutoshi TOMINAGA ◽  
...  

2012 ◽  
Vol 602-604 ◽  
pp. 1546-1554
Author(s):  
Donato Cancellara ◽  
Fabio de Angelis ◽  
Mario Pasquino

In this paper we have analyzed the influence of the strain hardening behavior of High Damping Rubber Bearings (HDRBs) adopted for a base isolation system of a Reinforced Concrete (RC) isolated structure. For the modeling of the rubber isolators we have adopted an evolution of the Bouc-Wen’s hysteretic model taking into account the incremental hardening effect which appears when the shear strain of the HDRB exceeds the limit value around 100% usually adopted in design practice. The incremental hardening effect is sometimes neglected in the design but it is an important aspect because it ensures a seismic protection of the base isolated structure also in presence of exceptional seismic events for intensity or frequency content. In this paper we have highlighted the significant influence of this phenomenon in the seismic response of the isolated structure by reporting the cyclic behavior of a HDRB respectively neglecting and considering this aspect.


2012 ◽  
Vol 19 (6) ◽  
pp. 1327-1339 ◽  
Author(s):  
Radhikesh P. Nanda ◽  
Pankaj Agarwal ◽  
Manish Shrikhande

A feasibility study of friction base isolation system for seismic protection has been performed. Four different sliding interfaces, namely, green marble/High Density Poly Ethylene (HDPE), green marble/green marble, green marble/geosynthetic, and green marble/ rubber layers have been studied through experimental and analytical investigations. The experimental investigations show that the coefficient of friction values of these interfaces lies in the desirable range for seismic protection, i.e., 0.05 to 0.15. The analytical investigation reveals that most of these sliding interfaces are effective in reducing spectral accelerations up to 50% and the sliding displacement is restricted within plinth projection of 75 mm (3 in). Green marble and geosynthetic are found to be better alternatives for use in friction isolation system with equal effectiveness of energy dissipation and limiting the earthquake energy transmission to super structure during strong earthquake leading to a low cost, durable solution for earthquake protection of masonry buildings.


1996 ◽  
Vol 2 (2) ◽  
pp. 69-73 ◽  
Author(s):  
Seiji TOMISHIMA ◽  
Shoji KATSUTA ◽  
Masayoshi HISANO

Author(s):  
Shun Suminokura ◽  
Katsumi Kurita ◽  
Shigeru Aoki ◽  
Yuji Nakanishi ◽  
Kazutoshi Tominaga ◽  
...  

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