1988 Fiscal Year Final Research Report Summary
Study on Seismic Behavior of Mechanical Snubbers
| Project/Area Number |
62550187
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| Research Category |
Grant-in-Aid for General Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Research Field |
機械力学・制御工学
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| Research Institution | Meiji University |
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Principal Investigator |
OHMATA Kenichiro Professor, Faculty of Engineering, Meiji Univ., 工学部, 教授 (10061954)
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| Co-Investigator(Kenkyū-buntansha) |
ARAKAWA Toshiharu Research Assistant, Faculty of Engineering, Meiji Univ., 工学部, 助手 (80159491)
SHIMODA Hirokazu Research Assistant, Faculty of Engineering, Meiji Univ., 工学部, 助手 (10130816)
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| Project Period (FY) |
1987 – 1988
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| Keywords | Mechanical Snubber / Mechanical Damper / Earthquakeproof Device / Piping / Earthquake Response / Nonlinear Vibration |
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| Research Abstract |
The mechanical snubber is an earthquakeproof device for piping systems under particular circumstances such as high temperature and radioactivity, and consists of a ball screw, a flywheel, a brake disk and brake shoe. It moves without any resitance in response to a slow movement such as thermal expansion of pipings and restrains displacement caused by a rapid movement such as earthquake. It has nonlinearities in both load and frequency response, so it will be very difficult to analyze the resisting force characteristics of the mechanical snubber theoretically.
In this research, the equation of motion of the mechanical snubber was derived and the resisting force characteristics of the snubber were simulated using Continuous System Simulation Language (CSSL). The digital simulations were carried out for various kinds of physical properties of the snubber and over a wide range. The earthquake responses of piping (a simply supported beam) which is supported by the snubber were also simulated using CSSL. The restraint effect and the maximum resisting force of the snubber during earthquake were discussed and compared with the case of an oil damper.
The resisting force characteristics of a snubber available in the market were measured using the vibration testing machine built as trial. The experimental results agreed fairly well with the results of the digital simulations, so that the validity of the digital simulations were substantiated.
Moreover, the effects of vibration isolation of a new type of mechanical damer which is composed of a ball screw, a flywheel and a vertically oscillating governor were discussed theoretically and experimentally. This damper acts as a snubber for larger values of the moment of inertia J of the flywheel and acts as general absorber for smaller values of J.
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Research Products
(6 results)
