2005 Fiscal Year Final Research Report Summary
Optimization research on the high-performance 3-dimensional base isolation system using a velocity reduction mechanism
| Project/Area Number |
15560203
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| Research Category |
Grant-in-Aid for Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
Dynamics/Control
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| Research Institution | Osaka prefecture university |
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Principal Investigator |
ITO Tomohiro Osaka prefecture university, Graduated School of Engineering, Professor, 工学研究科, 教授 (60347507)
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| Co-Investigator(Kenkyū-buntansha) |
FUJITA Katsuhisa Osaka prefecture university, Graduated School of Engineering, Professor, 工学研究科, 教授 (50295713)
SHINTANI Atsuhiko Osaka prefecture university, Graduated School of Engineering, Teaching Associate, 工学研究科, 助手 (90295725)
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| Project Period (FY) |
2003 – 2005
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| Keywords | 3-dimensional base isolation / optimization / rocking motion / friction damper / connecting shaft / spiral spring / horizontal and vertical coupled vibration / comfortableness |
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| Research Abstract |
The purpose of this study is to develop a new 3-dimensional base isolation system using a velocity reduction mechanism and to establish a fundamental technologies for actual application.
In 2003, the effects of the friction damper for response displacement and response acceleration, the effects of the connecting shaft for rocking suppression are studied numerically. From these results, the horizontal, vertical isolation capability are confirmed. And the isolation capability for the horizontal and vertical simultaneous excitation is also confirmed.
In 2004, the isolation capabilities for the various seismic waves with different frequency components such as Hyogoken Nambu Earthquake and Shiigata Chuetu Earthquake are evaluated numerically. It is considered that for the base isolation systems using sliding pads, the horizontal response will coupled with the vertical response, because the horizontal friction force will change according to the vertical response acceleration. Thus, numerical s
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imulations are performed for the seismic input waves with various phase differences and amplitudes, and the effects of the friction force change on the isolation characteristics are clarified. Moreover, a 1/4 scale model is fabricated and the seismic excitation tests are performed using a vertical shaking table. In the previous tests, the disadvantages of the worm gear system are found. Then, the other velocity reduction system is established using a spiral springs. Using this new system, the vertical isolation capability is also confirmed experimentally.
In 2005, the test apparatus is modified furthermore and the horizontal isolation capability and the horizontal/vertical isolation capability are confirmed. In this tests, the excitation frequency, excitation amplitude and the mass eccentricity are varied. And in the numerical simulations, the response of the human living in the isolated houses is also evaluated.
From these studies, the fundamental data are obtained for the optimization of the newly developed 3-dimensional base isolation system. Less
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