Assessment of Seismic Fragility Using a Three-Dimensional Structural Model of a Reactor Building

2021 ◽  
Author(s):  
Akemi Nishida ◽  
Byunghyun Choi ◽  
Tadahiko Shiomi ◽  
Manabu Kawata ◽  
Yinsheng Li
Keyword(s):  
Seismic Response ◽  
Evaluation Method ◽  
Structural Model ◽  
Three Dimensional ◽  
Response Assessment ◽  
Seismic Fragility ◽  
Response Analysis ◽  
Seismic Response Analysis ◽  
Seismic Safety ◽  
Reactor Building

Abstract New regulatory requirements in Japan have strengthened the mitigation of damage caused by natural hazards, such as earthquakes, and the operational guide for safety improvement evaluation recommends the use of a probabilistic risk assessment (PRA) as the evaluation method in Japan. In the PRA of an earthquake, also known as the seismic PRA, one of the most important issues is the realistic assessment of the structural seismic response and the conditional damage probability (fragility) assessment using a realistic response assessment of nuclear buildings and equipment. Accordingly, we conducted this study both on the analysis methods used for realistic seismic response and assessment methods of seismic fragility to ensure the seismic safety of nuclear buildings and equipment. In this study, we use a three-dimensional (3D) structural model of a reactor building to conduct a nonlinear seismic response analysis for input ground motions beyond a design basis. In addition, we identify the failure mode of the structural components of the reactor building associated with the equipment and assess the seismic fragility based on the 3D behavior of the reactor building. The local response and detailed damage progress of the reactor building obtained through seismic response analysis are reported, along with the results of the seismic fragility assessment.

Full Three-Dimensional Seismic Response Analysis of Underground Structures with Large Complex Cross Sections and Two-Step Analysis Method for Reducing the Computational Costs

2016 ◽  
Vol 10 (05) ◽  
pp. 1640016
Author(s):  
Tsuyoshi Ichimura ◽  
Seizo Tanaka ◽  
Muneo Hori ◽  
Yujin Yamamoto ◽  
Hiroshi Dobashi ◽  
...  
Keyword(s):  
Quality Assurance ◽  
Seismic Response ◽  
Three Dimensional ◽  
Response Analysis ◽  
3D Seismic ◽  
Underground Structures ◽  
Seismic Response Analysis ◽  
Seismic Safety ◽  
Computational Costs ◽  
Complex Cross

To enhance the reliability of estimates of seismic behavior, with a special emphasis on quality assurance of numerical simulations, this paper presents a full three-dimensional (3D) seismic response analysis of a large underground structure with a complex cross section. We conduct a full 3D seismic-response analysis using a high-fidelity model with quality assurance and a high-performance computing technique in a supercomputer environment. Due to the large computational costs of such analyses, we propose a two-step numerical simulation method based on multi-scale analysis, image-based modeling, and sophisticated approximation techniques. We provide numerical examples showing that the method can successfully reproduce the dynamic behavior of a full 3D model, but with a considerable reduction in computational costs. Our method is expected to support practical seismic safety inspections and the design of underground structures with complex large-cross-sectional configurations, as it has already been applied to the practical seismic safety inspection of an actual underground highway.

Seismic Response Analysis on Flat L-Shaped Frame Structure Based on FEM

2012 ◽  
Vol 166-169 ◽  
pp. 2138-2142
Author(s):  
Hui Min Wang ◽  
Liang Cao ◽  
Ji Yao ◽  
Zhi Liang Wang
Keyword(s):  
Seismic Response ◽  
Three Dimensional ◽  
Time History ◽  
Frame Structure ◽  
Response Analysis ◽  
Reinforced Concrete Frame ◽  
Seismic Response Analysis ◽  
Concrete Frame ◽  
History Analysis ◽  
Complex Features

For the complex features in the form of a flat L-shaped reinforced concrete frame structure, the three dimensional FEM model of the structure was established in this paper, and the dynamic characteristics of the structure was analyzed, the participation equivalent mass of every mode’s order was obtained. Seismic response analysis for the structure was carried out with modal decomposition spectrum method and time history analysis method, the weak layer of the structure was pointed out and the reference for the structural design was provided.

Research and Development of Three-Dimensional Isolation System for Sodium-Cooled Fast Reactor: Part 1 — Proposal of Analytical Models Based on Loading Tests

2018 ◽  
Author(s):  
Tsuyoshi Fukasawa ◽  
Shigeki Okamura ◽  
Takahiro Somaki ◽  
Takayuki Miyagawa ◽  
Masato Uchita ◽  
...  
Keyword(s):  
Seismic Response ◽  
Analytical Model ◽  
Three Dimensional ◽  
Analytical Models ◽  
Response Analysis ◽  
Seismic Response Analysis ◽  
Natural Period ◽  
Isolation System ◽  
Loading Tests ◽  
Rubber Bearings

This paper describes that the analytical model for the three-dimensional isolation system [1], which consists of thick rubber bearings, disc springs and oil dampers, is created through loading tests. The new-type analytical models of each element are proposed to improve the prediction accuracy of the seismic response analysis. The concept of the three-dimensional isolation system has been proposed to ensure the structural integrity for large reactor vessels. The primary specifications of the three-dimensional isolation system are a horizontal natural period of 3.4 s and a vertical natural period of 0.33 s. The investigations of horizontal isolation performances have been conducted for the various types of isolation devices, beginning with rubber bearings, whereas the previous studies focused on the vertical isolation performances are only a few. Hence, isolation characteristics, such as restoring force and damping force, should be clarified by loading tests using vertical seismic isolation elements, and analytical model to assess the seismic response should be identified on the basis of the loading test results. This paper presents a new analytical model with providing of the differential equations to improve the prediction accuracy and demonstrates the seismic performance, including beyond-design-basis ground motion, for the three-dimensional isolation system by the seismic response analysis.

A Parametric Study for the Seismic Response Analysis of a Nuclear Reactor Building by Using a Three-Dimensional Finite Element Model

2016 ◽  
Author(s):  
Byunghyun Choi ◽  
Akemi Nishida ◽  
Norihiro Nakajima
Keyword(s):  
Finite Element ◽  
Research And Development ◽  
Finite Element Model ◽  
Seismic Response ◽  
Parametric Study ◽  
Three Dimensional ◽  
Element Model ◽  
Response Analysis ◽  
Seismic Response Analysis ◽  
Uncertainty Parameters

Research and development of three-dimensional vibration simulation technologies for nuclear facilities is one mission of 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 JAEA during the 2011 Tohoku earthquake. In this paper, we report a seismic response analysis of this earthquake using three-dimensional models of the HTTR building. We performed a parametric study by using uncertainty parameters. Furthermore, we examined the variation in the response result for the uncertainty parameters to create a valid 3D finite element model.

Seismic Response Analysis of Large Liquid Storage Tanks

2012 ◽  
Vol 166-169 ◽  
pp. 2490-2493
Author(s):  
Yuan Zhang ◽  
You Hai Guan
Keyword(s):  
Seismic Response ◽  
Seismic Design ◽  
Storage Tank ◽  
Response Analysis ◽  
Storage Tanks ◽  
Performance Study ◽  
Seismic Response Analysis ◽  
Seismic Safety ◽  
Liquid Storage ◽  
Liquid Storage Tank

Due to frequent earthquakes in recent years, the seismic safety of large storage tank is very important. In this paper, seismic response of large liquid storage tanks is analyzed. A model for liquid storage tank is established firstly. By modality analysis, dynamic behavior of large storage tank is obtained. After the model is excitated by seismic, seismic responses are obtained. The conclusions show that, without considering liquid-solid coupling, "elephant foot" buckling phenomenon doesn’t appear. This study provides reference for seismic design and seismic performance study of large storage tank.

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