Refine your search:     
Report No.
 - 
Search Results: Records 1-20 displayed on this page of 149

Presentation/Publication Type

Initialising ...

Refine

Journal/Book Title

Initialising ...

Meeting title

Initialising ...

First Author

Initialising ...

Keyword

Initialising ...

Language

Initialising ...

Publication Year

Initialising ...

Held year of conference

Initialising ...

Save select records

Journal Articles

Application of analysis for assembly of integrated components to steel member connections towards seismic safety assessment of plant structures

Nishida, Akemi; Murakami, Takahiro*; Satoda, Akira*; Asano, Yuya*; Guo, Z.*; Matsukawa, Keisuke*; Oshima, Masami*; Nakajima, Norihiro

Proceedings of 25th International Conference on Structural Mechanics in Reactor Technology (SMiRT-25) (USB Flash Drive), 10 Pages, 2019/08

Exhaustive studies on external events that may pose a threat to the structures of nuclear facilities and evaluations of the structural integrities are critical to safety. One of the components that greatly influence the behavior of the plant structure is the connection of structural members. In particular, the modeling of the connections has relied on empirical methods, and been conservatively designed and evaluated by considering them as pinned or rigid connections. Therefore, in this research, we have aimed to develop a connection modeling method that reproduces more realistic behavior by utilizing a three-dimensional model of the connection. As the first step of this research, we planned to determine the stiffness of the connections of steel structural members. The results confirmed that the connection can be regarded as a partially-restrained connection depending on the connection specifications of the structure, and the prospects for realistic stiffness evaluation of the connection were determined.

Journal Articles

Visiting Professor's Research Division

Nakajima, Norihiro; Aoki, Keiko*

Tokyo Daigaku Jinkobutsu Kogaku Kenkyu Senta 2017-Nendo Kenkyu Nempo, p.51 - 53, 84, 2018/12

Visiting professors research division in the Research into Artifacts, Center for Engineering (RACE) has been conducting research collaboration in Socio-Artifactology and Human-Artifactology, in order to establish the methodology of the fusion research in sociology and science for artifacts engineering for the third era activity of RACE. The division decided to observe how the methodology works in applications with social experiments and numerical experiments for 2017.

Journal Articles

Data analysis based upon abduction; For better understanding the result discussion in computational science and engineering

Nakajima, Norihiro

Nihon Genshiryoku Gakkai-Shi ATOMO$$Sigma$$, 59(8), p.34 - 38, 2017/08

It is necessary the reading comprehension of output data to utilize the simulation in a design process, besides of the input data preparation. The simulation introduces enormous big data for evaluation. This paper describes data analysis technology in the analysis and the evaluation process of the output. The technology applies the artificial intelligence to minimize the unpredictable issues and oversight. It is based on the artifact engineering, which is a multi-sight abduction methodology, which derives a hypothesis.

Journal Articles

A Sensitivity analysis for construction of the seismic response analysis model of a nuclear reactor building by using a three-dimensional finite element model

Choi, B.; Nishida, Akemi; Nakajima, Norihiro

Kozo Kogaku Rombunshu, B, 63B, p.325 - 333, 2017/03

The Japan Atomic Energy Agency promotes research and development of three-dimensional vibration simulation technologies for nuclear facilities. In this paper, we report a seismic response analysis of the Tohoku Pacific Coast Earthquake using three-dimensional models of the High-Temperature Engineering Test Reactor (HTTR) building. We conducted a sensitivity study using input parameters with uncertainty. Furthermore, we examined the variation of the seismic response results against the input parameters.

Journal Articles

Investigation of error estimation method of observational data and comparison method between numerical and observational results toward V&V of seismic simulation

Suzuki, Yoshio; Kawakami, Yoshiaki*; Nakajima, Norihiro

Mechanical Engineering Reviews, 4(1), p.15-00525_1 - 15-00525_18, 2017/01

The method to estimate errors included in observational data and the method to compare numerical results with observational results are investigated toward the verification and validation (V&V) of a seismic simulation. For the method to estimate errors, it is found that errors are caused by the resolution, the linearity, the temperature coefficient for sensitivity, the temperature coefficient for zero shift, the transverse sensitivity, the seismometer property, the aliasing, and so on. Thus, it is needed to estimate errors individually for those factors and integrate them. For the method to compare numerical results with observational results, it is found that six methods have been mainly proposed in existing researches. Evaluating those methods using nine items, advantages and disadvantages for those methods are arranged. The method is not well established so that it is necessary to employ those methods by compensating disadvantages and/or to search for a solution to a novel method.

Journal Articles

Visualization in response analyses for a nuclear power plant

Nakajima, Norihiro; Nishida, Akemi; Miyamura, Hiroko; Iigaki, Kazuhiko; Sawa, Kazuhiro

Kashika Joho Gakkai-Shi (USB Flash Drive), 36(Suppl.2), 4 Pages, 2016/10

Since nuclear power plants have dimensions approximately 100m$$^{3}$$ and their structures are an assembly made up of over 10 million components, it is not convenient to experimentally analyze its behavior under strong loads of earthquakes, due to the complexity and hugeness of plants. The proposed system performs numerical simulations to evaluate the behaviors of an assembly like a nuclear facility. The paper discusses how to carry out visual analysis for assembly such as nuclear power plants. In a result discussion, a numerical experiment was carried out with a numerical model of High Temperature engineering Test Reactor of Japan Atomic Energy Agency and its result was compared with observed data. A good corresponding among them was obtained as a structural analysis of an assembly by using visualization. As a conclusion, a visual analytics methodology for assembly is discussed.

Journal Articles

A Parametric study for the seismic response analysis of a nuclear reactor building by using a three-dimensional finite element model

Choi, B.; Nishida, Akemi; Nakajima, Norihiro

Proceedings of 24th International Conference on Nuclear Engineering (ICONE-24) (DVD-ROM), 7 Pages, 2016/06

Research and development of three-dimensional vibration simulation technologies for nuclear facilities have been promoted in the Center for Computational Science and e-Systems of the Japan Atomic Energy Agency (JAEA). A seismic intensity of upper 5 was observed in the area of High-Temperature Engineering Test Reactor (HTTR) at the Oarai Research and Development Center of the JAEA during the 2011 Tohoku earthquake. In this paper, we report a parametric study of seismic response analyses of this earthquake using three-dimensional finite element models of the HTTR building with various uncertainty parameters (e.g. soil-structure interaction effects, soil properties). By examining the variation of the response result against the uncertainty parameters, we obtained a knowledge, which is essential for constructing a valid three-dimensional finite element model.

Journal Articles

An Illustration by the next generation numerical simulator for quake-proofing on the K

Nakajima, Norihiro; Suzuki, Yoshio; Miyamura, Hiroko; Nishida, Akemi; Kawakami, Yoshiaki; Guo, Z.; Tomiyama, Eiji*

Keisan Kogaku, 20(4), p.3338 - 3340, 2015/12

The issue 5 in the field 4 of "Monodukuri" in the HPCI strategy project is introduced. The title of the issue 5 is "research and development for the next-generation earthquake-resistant simulation of the large plants such as nuclear energy facilities". The illustration intends for a high temperature engineering examination research reactor. Implementation of FIESTA (Finite Element Analysis for Structure of Assembly) on K is described by reporting its efficiency and performance. To show a result of the numerical analysis, a visualization technique for the big data was described.

Journal Articles

Time domain response analysis for assembly by integrating components

Nakajima, Norihiro; Nishida, Akemi; Kawakami, Yoshiaki; Suzuki, Yoshio; Matsukawa, Keisuke*; Oshima, Masami*; Izuchi, Hisao*

Transactions of 23rd International Conference on Structural Mechanics in Reactor Technology (SMiRT-23) (USB Flash Drive), 10 Pages, 2015/08

The digital shaking table is introduced to carry out numerical experiments for the so called STRUCTURE of a petroleum plant. In numerical experiments, STRUCTURE was precisely modelled as it is designed and meshed into fine finite elements. The components of STRUCTURE were meshed one by one, and the code of a finite element analysis for structure of assembly gathered every meshed components to run time domain response analysis. Four waves are applied to the analysis to determine its behaviour. Four waves are namely as El Centro, Taft, Hachinohe, and Geiyo. The results of experiments are discussed by comparing accumulating data in the past. It is concluded to reconfirm the methodology of gathering meshed components and a finite element analysis for structure of assembly with the STRUCTURE.

Journal Articles

Analyses for designing objects in mechanical design

Nakajima, Norihiro; Miyamura, Hiroko; Kawakami, Yoshiaki; Kawamura, Takuma

Kashika Joho Gakkai-Shi, 35(Suppl.1), p.233 - 238, 2015/07

no abstracts in English

Journal Articles

Visiting Professor's Research Division

Nakajima, Norihiro; Aoki, Keiko*

Tokyo Daigaku Jinkobutsu Kogaku Kenkyu Senta 2014-Nendo Kenkyu Nempo, p.41 - 43, 2015/06

The activity in Visiting Professor Research Division is reported. In the third period, a methodology in the socio-scoence is suggested. Socio-Artifactology with Human-Artifactology is the main mission to be revealed.

Journal Articles

Seismic response simulation of High-Temperature Engineering Test Reactor building against 2011 Tohoku earthquake

Nishida, Akemi; Nakajima, Norihiro; Kawakami, Yoshiaki; Iigaki, Kazuhiko; Sawa, Kazuhiro

Proceedings of 23rd International Conference on Nuclear Engineering (ICONE-23) (DVD-ROM), 7 Pages, 2015/05

The R&D on the three dimensional vibration simulation technologies for a nuclear facility is one of missions of Center for Computational Science and e-Systems, Japan Atomic Energy Agency. Until now, three dimensional building and equipment models of HTTR (High Temperature Engineering Test Reactor) have been constructed and been performed validation of the models by comparison with seismic observed records. In this report, the results obtained by seismic observation simulation on the Tohoku earthquake occurred in the 3/11/2011 using three dimensional models of the HTTR building are shown. The simulation results show good agreement with the real observation data.

Journal Articles

Numerical modeling assistance system in finite element analysis for the structure of an assembly

Nakajima, Norihiro; Nishida, Akemi; Kawakami, Yoshiaki; Suzuki, Yoshio; Sawa, Kazuhiro; Iigaki, Kazuhiko

Proceedings of 23rd International Conference on Nuclear Engineering (ICONE-23) (DVD-ROM), 5 Pages, 2015/05

A numerical analysis controlling and managing system is implemented on K, which controls the modelling process and data treating, although the manager only controls a structural analysis by finite element method. The modeling process is described by the list of function ID and its procedures in a data base. The manager executes the process by order in the list for simulation procedures. The manager controls the intention of an analysis by changing the analytical process one to another. Experiments were carried out with static and dynamic analyses.

Journal Articles

Development of numerical modeling assistance system for finite element analysis

Nakajima, Norihiro; Nishida, Akemi; Kawakami, Yoshiaki; Suzuki, Yoshio

Nihon Kikai Gakkai Dai-24-Kai Sekkei Kogaku, Shisutemu Bumon Koenkai Koen Rombunshu (USB Flash Drive), 9 Pages, 2014/09

In this paper, a numerical analysis's controlling and managing system is suggested, which controls the modelling process and data treating for structural robustness, although a numerical analysis's manager only controls a structural analysis by finite element method. The modeling process is described by the list of function ID and its procedures in a data base. The analytical modeling manager executes the process by order of the lists for simulation procedures. The manager controls the intention of an analysis by changing the analytical process one to another. Modeling process was experimentally found that may subject to the intention of designing index. In the numerical experiments, K, supercomputer is utilized by using parallel computing resource with the controlling and managing system.

Journal Articles

Structural analysis for assembly by integrating parts

Nakajima, Norihiro; Nishida, Akemi; Kawakami, Yoshiaki; Okada, Tatsuo*; Tsuruta, Osamu*; Sawa, Kazuhiro; Iigaki, Kazuhiko

Proceedings of 22nd International Conference on Nuclear Engineering (ICONE-22) (DVD-ROM), 9 Pages, 2014/07

Almost all industrial products are assembled from multiple parts. A nuclear facility is a large structure consisting of more than 10 million components. This paper discusses a method to analyze an assembly by gathering data on its component parts. Gathered data on component may identify ill conditioned meshes for connecting surfaces between components. These ill meshes are typified by nodal point disagreement in finite element discretization. A technique to resolve inconsistencies in data among the components is developed. By using this technique, structural analysis for an assembly can be carried out, and results can be obtained by the use of supercomputers, such as the K computer. Numerical results are discussed for components of the High Temperature Engineering Test Reactor.

Journal Articles

A Quake-proof analysis for a plant as an assembly in the next generation

Nakajima, Norihiro; Nishida, Akemi; Kawakami, Yoshiaki; Okada, Tatsuo; Tsuruta, Osamu; Sawa, Kazuhiro; Iigaki, Kazuhiko

Tabo Kikai, 42(5), p.332 - 338, 2014/05

K computer is one of the highest performance computers in the world. This paper discusses one of R&D issues in K computer national project. Industrial products are an artifact, which are assembly consisting of simple components more than at least two regardless of the big products and small products. In the nuclear industry, the facilities are large structures consisting of over 10 millions of components, since they are engaged with the highest technology and for safety sake. This paper introduces a method to analyze an assembly by gathering its components data. In the manner of gathering components data, it is raised many issues to concern among components. It is developed a technique to solve the inconsistent data among the components. By using this technique, a structural analysis for an assembly is done by using K computer. Numerical results are presented in the case of analysis for High Temperature engineering Test Reactor's components.

Journal Articles

Analysis by computational science and technology viewpoint

Nakajima, Norihiro

Fukushima Daiichi Genshiryoku Hatsudensho Jiko: Sono Zenbo To Asu Ni Muketa Teigen; Gakkai Jikocho Saishu Hokokusho, p.228 - 237, 2014/03

As a group of experts of the nuclear science and technology, AESJ (Atomic Energy Society of Japan) realized responsibility for a nuclear-power disaster, and participated in the convergence of the accident and an environmental remediation since the outbreak of the accident positively and worked on activity in order to achieve the duty. As the part, AESJ started "investigation committee about the Tokyo Electric Power Fukushima the first Nuclear Power Plant accident" (2012) on June 22 in 2012. The committee gathered from divisional meetings and liaison meetings, the committee which constituted a society and pushed forward activity. AESJ stands in the reflection that was not able to prevent this accident as a scientific group of experts of the fields of atomic energy, and, separately from various accident investigation of the above, deep analysis investigates an accident phenomenon and the influence from a specialized viewpoint.

Journal Articles

Assembly structure analysis system

Nakajima, Norihiro; Nishida, Akemi; Matsubara, Hitoshi*; Hazama, Osamu*; Suzuki, Yoshio; Sawa, Kazuhiro; Iigaki, Kazuhiko

Transactions of 22nd International Conference on Structural Mechanics in Reactor Technology (SMiRT-22) (CD-ROM), 10 Pages, 2013/08

It is not convenient to experimentally analyze its behavior under strong loads of earthquakes, since the facility is extremely huge and complex. The proposed system performs numerical simulations to evaluate the behaviors of an assembly like a nuclear facility. This system projects the components of an assembly onto both/either a distributed and/or a parallel computing environment in order to conduct a simulation of the behavior of an assembly such as a nuclear facility. In a result discussion, a numerical experiment was carried out with a cantilever model and its result was compared with theoretical data. A good corresponding among them was obtained as a structural analysis of an assembly by using a parallel computer. As a conclusion, a suggested methodology has shown to calculate a behavior of an assembly with High Temperature engineering Test Reactor.

Journal Articles

Research and development of full-scale three-dimensional vibration simulator for nuclear plant

Nishida, Akemi; Suzuki, Yoshio; Yamada, Tomonori; Kino, Chiaki; Uzawa, Ken*; Miyamura, Hiroko; Kawamura, Takuma; Takemiya, Hiroshi; Nakajima, Norihiro

RIST News, (54), p.33 - 37, 2013/01

Nuclear plants are complicated and huge structures and consist of a large number of parts. To simulate the behavior of such a complicated huge structure, it becomes important the viewpoint as a general system including pre-post-processing. Therefore, the CCSE proposed an approach for assembly structure analysis and implemented a framework of a full-scale 3D vibration simulator for an entire nuclear plant. Until now, we performed numerical experiments using the data of a building and equipment of HTTR, Oarai R&D Center, JAEA, and demonstrated that earthquake response simulation of large-scale structure as an entire nuclear plant was possible so far. In this report, the framework of the full-scale 3D vibration simulator, the assembly structure analysis approach and visualization technology for an evaluation of the results are shown. And finally, an example of application of the simulator for probabilistic risk assessment, PRA, started from 2011, is shown.

Journal Articles

R&D of a zooming analysis to verify a seismic simulation of an entire nuclear plant

Suzuki, Yoshio; Hoshi, Yoshiyuki*; Sakamoto, Kensaku; Nakajima, Norihiro

Proceedings of 4th International Conference on Computational Methods (ICCM 2012) (USB Flash Drive), 9 Pages, 2012/11

We research and develop a three-dimensional vibration simulator for an entire nuclear plant aiming at technical advances for more rational safety assessment of nuclear plant under an earthquake. The simulator includes "an entire structural simulation of ground-building-equipments (beam model)" and "an assembly structural simulation of parts to equipments (solid model)". As one approach to examine the quality of solid model which consists of thousands of parts, we have established a trial tool to perform the assembly structural simulation for a small number of parts by zooming in on a part of equipments in the entire structural simulation, and to compare results. To verify the tool, we applied the tool to static and dynamic simulations for a cantilever with various cross sections, and a static simulation of a small number of parts of nuclear plant, and confirmed results for solid model well coincide with those for beam model.

149 (Records 1-20 displayed on this page)