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Miyazaki, Akemi; Tsuru, Hideo*
Dai-56-Kai Riron Oyo Rikigaku Koenkai Koen Rombunshu, p.299 - 300, 2007/03
The author has researched stress wave propagation in frame structures in order to clarify the dynamic behavior of complicated assembled structures. A spectrum element method (SEM) has been adopted as one of the effective methods, and numerical simulations of a real-sized piping structure has been performed. The Timoshenko theory is usually used in wave propagation analysis of frame structures because it can relatively well approximate in high frequency domain. The theory uses a so-called Timoshenko coefficient to couple the bending and shear deformation. This coefficient is calculated using the shear deformation distribution within the cross section. In this paper, we re-examined the Cowper's theory which introduced the least assumptions in computing the Timoshenko coefficient. The connection between cross section and dispersion relation was investigated and a numerical simulation was attempted. An importance of an estimation of Timoshenko coefficient was discussed.
Miyazaki, Akemi
Kozo Kogaku Rombunshu, B, 52B, p.119 - 124, 2006/03
Since it is generally difficult to predict the occurrence of natural disasters such as earthquakes, a performance management system that always maintains the safety and functionalities of structures is required, especially for critical ones like nuclear power plants. In order to realize such a system, it is becoming important to carry out modeling procedures and analyses in detail to better understand the real phenomena. Such details are important in understanding the phenomena occurring in frame structures such as piping systems which are considered to be one of the vulnerable parts in nuclear power plants. The aim of our research is to solve the dynamic behavior of piping systems in nuclear power plants which are complicated assemblages of parts. The spectral element method is adopted in this work and the formulation considering a shear deformation of a frame element is described. The Timoshenko beam theory is introduced for the purpose of this formulation. The validity of the presented element will be shown through comparisons made with the conventional beam.
Miyazaki, Akemi; Kawaguchi, Kenichi*
Nihon Kenchiku Gakkai Kozokei Rombunshu, 597, p.69 - 76, 2005/11
The objective of our research is to examine the wave propagation properties of framed structures. Those structures tend to become larger and higher recently. On the case of those structures it may be possible that the structure is locally damaged before it becomes vibration state by an external force. It is seemed that for such structures then the investigation and estimation of dynamic structural behaviour from the view point of wave propagation become important. For these purposes, we planned and carried out impact hammer experiments on some lattice-type plates. In this paper the experiment results performed on three lattice-type plates and one continuum plate are shown. The results show that wave propagation properties of lattice-type plates depend on wave propagation properties of the members consist of those lattice-type plates. Preliminary experiments for evaluating the effect of the boundary conditions performed in advance of the experiments for lattice-type plate models are also shown.
Miyazaki, Akemi
Proceedings of 13th International Conference on Nuclear Engineering (ICONE-13) (CD-ROM), 6 Pages, 2005/05
Since it is generally difficult to predict the occurrence of the natural disasters such as earthquakes, a performance management system that always maintains the safety of the structures is required, especially for the critical ones like the nuclear power plants. To realize such a system, it is becoming important to carry out modeling procedures and analyses in detail to capture the real phenomena. Such details are important in understanding the phenomena occurring in the frame structures such as piping systems which are considered to be one of the most weakest and vulnerable parts in the nuclear power plants. The aim of our research is to solve the dynamic behavior, especially the wave propagation phenomena for the piping systems in the nuclear power. The spectral element method is adopted in this work and the formulation considering a shear deformation of a frame element is described. Timoshenko beam theory is introduced for the purpose of this formulation. The validity of the presented element will be shown through the comparisons made with the conventional beam element.
Nakajima, Norihiro; Suzuki, Yoshio; Kushida, Noriyuki; Matsubara, Hitoshi; Nakajima, Kohei; Tani, Masayuki; Miyazaki, Akemi; Tian, R.; Hazama, Osamu
no journal, ,
no abstracts in English
Tian, R.; Miyazaki, Akemi; Matsubara, Hitoshi; Nakajima, Norihiro; Tani, Masayuki
no journal, ,
A nuclear power plant is made up of numerous components that are interconnected to each other. Upon external load, they act in a certain interactive way to bear the external load. Therefore, it is an important issue to understand the interaction effect and integrated behaviors of these components. At the current stage, a nuclear power plant is assumed to be a unified structure, and hence it is impossible to evaluate the interaction effects among these components. We have recently established a new approach called assembled structure analysis. In this talk, we will give an introduction of the outline of the entire nuclear power plant simulation system and the fundamental system design of the connection effect evaluation methods.
Miyazaki, Akemi; Tian, R.; Matsubara, Hitoshi; Nakajima, Norihiro; Tani, Masayuki
no journal, ,
A nuclear power plant is made up of numerous components that are interconnected to each other. Upon external load, they act in a certain interactive way to bear the external load. Therefore, it is an important issue to understand the interaction effect and integrated behaviors of these components. At the current stage, a nuclear power plant is assumed to be a unified structure, and hence it is impossible to evaluate the interaction effects among these components. We have recently established a new approach called assembled structure analysis. In this presentation, we will demonstrate the static simulation results of stresses/strain of the cooling system of the nuclear power plant, and show the great possibility of modeling the nuclear power plant in entire in near future.
Miyazaki, Akemi; Suzuki, Yoshio; Matsubara, Hitoshi; Tian, R.; Hazama, Osamu; Tani, Masayuki; Nakajima, Norihiro
no journal, ,
Nuclear power plants are large-scale complicated structures comprising many components. The connections between these components are one of the weakest parts of a nuclear power plant. Further, these parts retain many unknown characteristics with respect to the dynamic properties of the connections. To apply a 3D virtual plant vibration simulator to the large-scale structural analysis of a nuclear power plant, a technology to consider the structure as an assemblage of components and to enable whole scale analysis of an extra-large plant by considering the interaction between its parts was developed and implemented on a prototype system on a grid environment. In this report, a system construction on a grid environment of an assembly structure is analyzed; further, an example of an application for the static structure analysis of a cooling system of a high temperature engineering test reactor (HTTR) of The Oarai Research and Development Center, JAEA is shown.
