Initialising ...
Initialising ...
Initialising ...
Initialising ...
Initialising ...
Initialising ...
Initialising ...
Masaki, Nobuo*; Kato, Koji*; Yamamoto, Tomohiko; Miyagawa, Takayuki*; Fujita, Satoshi*; Okamura, Shigeki*
Nihon Kenchiku Gakkai Gijutsu Hokokushu, 28(68), p.81 - 84, 2022/02
no abstracts in English
Furuya, Osamu*; Fujita, Satoshi*; Muta, Hitoshi*; Otori, Yasuki*; Itoi, Tatsuya*; Okamura, Shigeki*; Minagawa, Keisuke*; Nakamura, Izumi*; Fujimoto, Shigeru*; Otani, Akihito*; et al.
Proceedings of ASME 2021 Pressure Vessels and Piping Conference (PVP 2021) (Internet), 6 Pages, 2021/07
Since the Fukushima accident, with the higher safety requirements of nuclear facilities in Japan, suppliers, manufacturers and academic societies have been actively considering the reconstruction of the safety of nuclear facilities from various perspectives. The Nuclear Regulation Authority has formulated new regulatory standards and is in operation. The new regulatory standards are based on defense in depth, and have significantly raised the levels of natural hazards and have requested to strengthen the countermeasures from the perspective of preventing the simultaneous loss of safety functions due to common factors. Facilities for dealing with specific serious accidents are required to have robustness to ensure functions against earthquakes that exceed the design standards to a certain extent. In addition, since the probabilistic risk assessment (PRA) and the safety margin evaluation are performed to include the range beyond the design assumption in the safety improvement evaluation, it is very important to extent the special knowledge in the strength of important equipment for seismic safety. This paper summarizes the research and examination results of specialized knowledge on the concept of maintaining the functions of important seismic facilities and the damage index to be considered by severe earthquakes. In the other paper, the study on reliability of seismic capacity analysis for important equipment in nuclear facilities will be reported.
Fukasawa, Tsuyoshi*; Miyagawa, Takayuki*; Uchita, Masato*; Yamamoto, Tomohiko; Miyazaki, Masashi; Okamura, Shigeki*; Fujita, Satoshi*
Nihon Kikai Gakkai Rombunshu (Internet), 87(898), p.21-00007_1 - 21-00007_17, 2021/06
This paper describes a fundamental study on the seismic safety margin for the isolated structure using laminated rubber bearings. The variation of the seismic response assumed in the isolated structure will occur under the superposition of "Variations in seismic response due to input ground motions" and "Error with design value accompanying manufacture of the isolation devices ". The seismic response analysis which allows to their conditions is important to assess the seismic safety margin for the isolated structure. This paper clarifies that the seismic safety margin of the isolated structure, which consists of rubber bearings, for Sodium-cooled Fast Reactor (SFR) is ensured against the basis ground motions of Japan Electric Association Guide 4601 (JEAG4601) and SFR through the seismic response analysis considering the variation factors of seismic response. In addition, a relationship between the seismic safety margin and the excess probability of linearity limits is discussed using the results of seismic response analysis.
Minagawa, Keisuke*; Fujita, Satoshi*; Kitamura, Seiji; Okamura, Shigeki
Proceedings of 2009 ASME Pressure Vessels and Piping Division Conference (PVP 2009) (CD-ROM), 7 Pages, 2009/07
Minagawa, Keisuke*; Fujita, Satoshi*; Kitamura, Seiji; Okamura, Shigeki
Proceedings of 2008 ASME Pressure Vessels and Piping Division Conference (PVP 2008) (CD-ROM), 6 Pages, 2008/08
Minagawa, Keisuke*; Fujita, Satoshi*; Kitamura, Seiji; Okamura, Shigeki
Transactions of the 19th International Conference on Structural Mechanics in Reactor Technology (SMiRT-19) (CD-ROM), 7 Pages, 2007/08
Although mechanical structures have sufficient seismic safety margin, comprehending the ultimate strength is very important in order to improve the seismic safety reliability in unexpected severe earthquake. The energy balance is adequate to investigate the influence of cumulative load because it includes cumulative information. The vibration experiments using simple single-degree-of-freedom experimental model are carried out in order to confirm a calculation technique of energy and to investigate behavior of energy in elasto-plastic region. The vibration failure experiments that lead experimental model to fatigue failure are carried out in order to investigate the relationship between input energy and fatigue failure.
Minagawa, Keisuke*; Fujita, Satoshi*; Kitamura, Seiji; Okamura, Shigeki
Proceedings of 2007 ASME Pressure Vessels and Piping Division Conference/8th International Conference on Creep and Fatigue at Elevated Temperatures (PVP 2007/CREEP-8) (CD-ROM), 6 Pages, 2007/07
This paper describes the dynamic strength evaluation of piping installed in nuclear power plants from a viewpoint of energy balance. In this study, ultimate strength of a simple single degree of freedom model is investigated from a viewpoint of energy balance equation that is one of valid methods for structural calculation. The investigation is implemented by forced vibration experiment. In the experiment, colored random wave having predominant frequency similar to natural frequency of the experimental model is input. Stainless steel and carbon steel are selected as material of experimental model. As a result of the experiment, it is confirmed that input energy for fracture increase with an increase of time for fracture. In other words, more input energy for fracture is needed in case of small input level. Additionally it is confirmed that input energy for fracture depend on the material.
Shindo, Masami; *; Kunitomi, Kazuhiko; ; Sawa, Kazuhiro
Nucl. Eng. Des., 132, p.39 - 45, 1991/00
Times Cited Count：5 Percentile：53.87(Nuclear Science & Technology)no abstracts in English
Shiina, Yasuaki; Kunitomi, Kazuhiko; Maruyama, So; ; Nakagawa, Shigeaki; Hirano, Masashi; Iyoku, Tatsuo; Shindo, Masami; Sudo, Yukio
JAERI-M 90-034, 104 Pages, 1990/03
no abstracts in English
; Suzuki, Takehiro*; *
JAERI-M 88-206, 20 Pages, 1988/10
no abstracts in English
; ; ; ; *; *; *; *
JAERI-M 86-166, 237 Pages, 1986/12
no abstracts in English
; *; ;
JAERI-M 85-185, 67 Pages, 1985/11
no abstracts in English
Minagawa, Keisuke*; Fujita, Satoshi*; Kitamura, Seiji; Okamura, Shigeki
no journal, ,
In this research, The strength evaluation technique for paying attention into energy is examined for the equipments and the piping in the nuclear power plant during the earthquakes. In this report, the shaking table tests for the one mass model were conducted, and the behavior of energy was examined.
Kitamura, Seiji; Okamura, Shigeki; Minagawa, Keisuke*; Fujita, Satoshi*
no journal, ,
The dynamic strength evaluation method that pays attention into energy is examined so that the equipment and piping in the nuclear power plant may clarify the condition to plasticity/destruction. It reports on the result of applying the idea of the energy evaluation to the dynamic excitation examination result of the Elbo element.
Minagawa, Keisuke*; Fujita, Satoshi*; Kitamura, Seiji; Okamura, Shigeki
no journal, ,
It proposes a dynamic strength evaluation method of the piping systems, and the effectiveness of this method is examined. In this report, the behavior of the energy at the vibration fatigue failure by the one mass model was examined.
Minagawa, Keisuke*; Fujita, Satoshi*; Kitamura, Seiji; Okamura, Shigeki
no journal, ,
Mechanical structures installed in nuclear power plants such as piping are usually designed staically in elastic region. Although these mechanical structures have sufficient seismic safety margin, comprehending the ultimate strength is very important in order to improve of the seismic safety reliability in unexpected severe earthquake. The ultimate strength of piping is investigated from the viewpoint of energy balance method in this research. Vibration fracture experiments that lead one mass model to fatigue fracture are carried out in order to investigate the relationship between input energy and fracture.
Minagawa, Keisuke*; Fujita, Satoshi*; Kitamura, Seiji; Okamura, Shigeki
no journal, ,
In this research, it has aimed to develop the dynamic strength evaluation of the piping system by using the energy balance equation. The relation between the fatigue failure and energy by the vibration has been investigated by having used one mass model up to now. The vibration experiment by the straight piping model was executed and it reports on the result of the arrangement by energy.
Yamamoto, Tomohiko; Watakabe, Tomoyoshi; Miyagawa, Takayuki*; Okamura, Shigeki*; Fukasawa, Tsuyoshi*; Fujita, Satoshi*
no journal, ,
This report describes that the concepts and specifications of "3-dimensional seismic isolation device" adopting in a Sodium-cooled fast reactor, summary of various tests and analyzes, and shows feasibility of 3-dimensional seismic isolation device for earthquake response reduction effect.
Yamamoto, Tomohiko; Watakabe, Tomoyoshi; Miyagawa, Takayuki*; Fukasawa, Tsuyoshi*; Okamura, Shigeki*; Fujita, Satoshi*
no journal, ,
This report describes that the concepts and specifications of "3-dimensional seismic isolation device" adopting in a Sodium-cooled fast reactor, summary of various tests and analyzes, and shows feasibility of 3-dimensional seismic isolation device for earthquake response reduction effect.
Okamura, Shigeki*; Fujita, Satoshi*; Uchita, Masato*; Fukasawa, Tsuyoshi*; Yamamoto, Tomohiko
no journal, ,
no abstracts in English
