著者

安田 正志 佐藤 栄児 山田 学 梶原 浩一 早津 昌樹

出版者

一般社団法人 日本機械学会

雑誌

日本機械学会論文集 (ISSN:21879761)

巻号頁・発行日

vol.84, no.861, pp.17-00509-17-00509, 2018 (Released:2018-05-25)

参考文献数

10

被引用文献数

2

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Research on seismic isolation technology was also a question of how much restoring force can be reduced. The seismic isolation rubber with thin film like rubber and metal plates stacked in multiple stages to reduce the restoring force has achieved great success. However, there still exists restoring power, measures against long-period earthquakes are not perfect and vertically unprotected. This research is an effort to make three-dimensional seismic isolation more realistic with higher performance by further minimizing resilience in all directions. The developed three-dimensional seismic isolation mechanism consists of an air levitation mechanism that isolates horizontal vibration and a spring link mechanism that isolates vertical vibration. Excitation experiments of the prototype were carried out using real-scale three-dimensional seismic waves by the E-defense shaking table. As a result, excellent characteristics of horizontal periodicity and vertical natural period of 5 s were confirmed. The vibration isolation performance at 1 Hz was about 20 dB in all three directions, and the high isolation performance not found in conventional equipment was verified. They were also supported by analytical models.

著者

安田 正志 佐藤 栄児 山田 学 梶原 浩一 早津 昌樹

出版者

一般社団法人 日本機械学会

雑誌

日本機械学会論文集 (ISSN:21879761)

巻号頁・発行日

vol.83, no.851, pp.17-00057-17-00057, 2017 (Released:2017-07-25)

参考文献数

10

被引用文献数

5

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Vibration tests of the prototype of the newly developed three-dimensional seismic isolation mechanism were carried out using several real-scale three-dimensional seismic waves with the world's largest E-defense shaking table. The developed 3-D seismic isolation mechanism has an air levitation mechanism that isolates horizontal vibration and a spring link mechanism that isolates vertical vibration, in series. The air levitation mechanism floats only 50 μm from the floor and is in contact with the floor with a slight air viscous force of a friction coefficient of 1/1000. Since there is no spring force in the horizontal direction in this mechanism, there is no periodic motion and there is no amplification of vibration. Also, since the floating height is very small, the vertical rigidity is very high even in the air, and the rocking motion is not performed. The spring link mechanism combines a negative stiffness link and a positive stiffness link to minimize the spring stiffness. While maintaining the horizontal attitude by the link, a vertical natural frequency of 0.25 Hz was realized. The prototype showed unprecedented high performance of about 20 dB of anti-vibration capability at 1 Hz both in the horizontal and vertical directions, and the effectiveness was verified in this experiment. The seismic waves used for the experiment are the Takatori seismic wave of the Great Hanshin-Awaji Earthquake of 1995 and the Sendai seismic wave of the Great East Japan Earthquake of 2011.