著者

飯島 直紀 渡邉 鉄也 成澤 慶宜

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.86, no.887, pp.20-00010, 2020 (Released:2020-07-25)

参考文献数

9

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This paper deals with seismic isolation system with nonlinear characteristics for vertical ground motion. The vertical seismic isolation system consists of a rhombus shaped link mechanism, a tension coil spring, and a leaf spring. The restoring force of the system is obtained by the sum of the restoring force of the buckling deformation of leaf spring and the restoring force of the rhombus shaped link. The purpose of this paper is to create design guidelines for seismic isolation system. Random waves were input to the experimental model with nonlinear restoring force, and the reduction effect was about 0.1 times. In addition, the validity of the analytical model was confirmed by comparing the experimental results with the calculated results. By setting dimensionless parameters and performing analysis, combinations of parameters with high seismic isolation effect were clarified. When the seismic isolation object was determined, a guideline on how to design it was given to make the seismic isolation design easier.

著者

成澤 慶宜 水野 毅 高崎 正也 石野 裕二 原 正之 山口 大介

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.17-00523-17-00523, 2018 (Released:2018-05-25)

参考文献数

17

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A basic single-degree-of-freedom magnetic suspension system consists of one floator, one electromagnet and one amplifier. For multi-degrees-of-freedom control, multiple electromagnets and multiple amplifiers are necessary, which increases the cost of total system. As a means of overcoming this problem, parallel magnetic suspension has been proposed which controls multiple floators or multi-degree-of-freedom motions with a single power amplifier. In this system, all of the suspended points move simultaneously even when a disturbance acts on one of the suspended points solely because all electromagnet's coils are connected. This paper studies the moving direction of each suspended point with respect to a step disturbance in double parallel magnetic suspension system. The analytical study shows that the response direction is determined by the system parameter that relates the response speed of each subsystem. In the slower subsystem, the suspended point moves in the same direction as the applied force while in the faster subsystem, the suspended point moves in the opposite direction. In other words, the slower subsystem has positive stiffness while the faster system has negative stiffness. To confirm this prediction, step responses are measured in the experimental apparatus.