scholarly journals 3D FEM Soil-Structure Interaction Analysis for Kashiwazaki–Kariwa Nuclear Power Plant Considering Soil Separation and Sliding

2021 ◽  
Vol 7 ◽  
Author(s):  
Yoshitaka Ichihara ◽  
Naohiro Nakamura ◽  
Hiroshi Moritani ◽  
Byunghyun Choi ◽  
Akemi Nishida
Keyword(s):  
Seismic Data ◽  
Nuclear Power ◽  
Soil Structure ◽  
Three Dimensional ◽  
Nonlinear Behavior ◽  
Element Model ◽  
Soil Structure Interaction ◽  
Reactor Building ◽  
Dimensional Finite Element ◽  
Three Dimensional Finite Element

In the 2007 Niigataken Chuetsu-oki earthquake, soil settlement, considered to be a result of the relative displacement between the soil and the structure, occurred alongside buildings at Kashiwazaki–Kariwa nuclear power plant. The objective of this study is to evaluate accurately the influence of the nonlinear behavior of the soil-structure interface on the response of the reactor building using a three-dimensional finite element model. To achieve this, we modeled the separation and sliding from sidewalls during a severe earthquake using joint elements, and evaluated the effect on the horizontal response of the structure. Through the soil-structure interaction analyses based on the recorded seismic data on the foundation for unit 7 reactor building using the three-dimensional finite element model, it was confirmed that the simulated horizontal responses of the building corresponded to the recorded seismic data. In addition, the comparison of the cases with and without separation and sliding revealed that the separation and sliding of soil from sidewalls reduces the embedment effects of the structure and that the reduction causes an occurrence of the foundation uplift. Moreover, in this study, it was clarified that the increase of the foundation uplift affected both the soil pressure characteristics beneath the foundation and along the sidewalls, and the maximum acceleration response of structures. In this study, the separation and sliding of soil from sidewalls had only a limited influence on the structural responses; however, under severe seismic excitation, it is expected that the embedment effects will be significantly reduced due to the separation and sliding of soil. Therefore, a precise response evaluation of the building including the nonlinear behavior due to separation and sliding should be considered in the seismic response analyses under severe seismic excitation.

Propagation of Buckles in Sandwich Pipes Under External Pressure

2005 ◽  
Author(s):  
I. P. Pasqualino ◽  
M. I. Lourenc¸o ◽  
T. A. Netto
Keyword(s):  
Three Dimensional ◽  
Nonlinear Behavior ◽  
Element Model ◽  
External Pressure ◽  
Core Material ◽  
Small Scale ◽  
Ongoing Research ◽  
Scale Models ◽  
Dimensional Finite Element ◽  
Three Dimensional Finite Element

Sandwich pipes have been considered feasible conceptions for ultra deepwater pipelines, since they are capable to work at low temperatures and withstand high hydrostatic pressures. Sandwich pipelines are composed by inner and outer metallic pipes and a suitable core material which must provide high compression strength and good thermal insulation. The aim of this ongoing research is to study the quasi-static propagation of buckles in sandwich pipes. In this paper, a three-dimensional finite element model considering material and geometric nonlinear behavior is presented. The mesh discretization is determined through a detailed mesh sensitivity analysis. Some experiments with small scale models combining aluminum pipes and polypropylene as core material were carried out to calibrate the numerical model. The propagation pressure is evaluated under different bonding conditions between pipe layers.

3D Numerical Analysis of Metro Station by PBA Method to Enlarge Existing Large-Size Shield Tunnel

2012 ◽  
Vol 170-173 ◽  
pp. 1673-1678
Author(s):  
Mei Yan ◽  
De Yun Ding ◽  
Xiu Ren Yang ◽  
Xiu Ren Yang ◽  
Wei Dong Lu ◽  
...  
Keyword(s):  
Soil Structure ◽  
Three Dimensional ◽  
Element Model ◽  
Shield Tunnel ◽  
Interaction Theory ◽  
Metro Station ◽  
Large Size ◽  
Dimensional Finite Element ◽  
Three Dimensional Finite Element ◽  
Station Structure

There is no engineering experience for metro station construction by the PBA (Pile-Beam-Arch) method to enlarge an existing large-size shield tunnel in China. During enlarging construction by the PBA method, the spatial mechanical and deformational characteristics of metro station structure are still not clear. In this paper, the Gaojiayuan station is taken as an engineering background to study the spatial mechanical and deformational characteristics during enlarging construction by the PBA method. Based on soil-structure interaction theory, a three-dimensional finite element model is built to simulate the enlarging construction by the PBA method. The three-dimensional numerical results can be regarded as a valuable reference for enlarging construction by the PBA method in Beijing metro line 14.

scholarly journals Nonsymmetric Nonlinear Dynamics of Piezoelectrically Actuated Beams

2019 ◽  
Vol 141 (5) ◽  
Author(s):  
Mergen H. Ghayesh ◽  
Hamed Farokhi
Keyword(s):  
Degrees Of Freedom ◽  
Three Dimensional ◽  
Nonlinear Behavior ◽  
Element Model ◽  
Piezoelectric Patch ◽  
Beam System ◽  
Piezoelectric Beam ◽  
Dimensional Finite Element ◽  
Differential Type ◽  
Three Dimensional Finite Element

The nonlinear behavior of a piezoelectrically actuated clamped–clamped beam has been examined numerically while highlighting the nonsymmetric response of the system. The nonlinearly coupled electromechanical model of the piezoelectric beam system is developed employing the Bernoulli–Euler theory along with the piezoelectric stress–voltage equations. A general nonsymmetric configuration is considered with a piezoelectric patch partially covering the beam. The geometric nonlinearities of stretching type are taken into account for both the piezoelectric patch and the beam. Through use of the generalized Hamilton's principle, the nonlinearly coupled electromechanical equations of transverse and longitudinal motions of the piezoelectrically actuated beam are derived. A high-dimensional Galerkin scheme is utilized to recast the equations of partial differential type into ordinary differential type. For comparison and benchmark purposes, a three-dimensional finite element model is developed using abaqus/cae to verify the model developed in this study. It is shown that the response of the system is strongly nonsymmetric and that it is essential to retain many degrees-of-freedom to ensure converged results.

scholarly journals Prediction and Measurement of Sealing Properties of Joints Between Wavy Metal Surfaces

2018 ◽  
Vol 140 (5) ◽  
Author(s):  
Julien Bourniquel ◽  
Didier Lasseux ◽  
Jean-Francois Rit
Keyword(s):  
Nuclear Power ◽  
Power Plants ◽  
Normal Load ◽  
Three Dimensional ◽  
Element Model ◽  
Lower Surface ◽  
Ring Shape ◽  
Metal Metal ◽  
Dimensional Finite Element ◽  
Three Dimensional Finite Element

The transmissivity of metal-metal sealing joints is investigated experimentally and compared to predictions obtained by modeling. The focus is laid upon a wavy surface contacting a flat rigid part, representative of a seat-to-plug contact in an internal sealing valve encountered in nuclear power plants for instance. Experimental transmissivities are obtained from water leak-rate and pressure drop measurements carried out on a model ring-shape sample seat holding a controlled wavy defect and pressed against a rigid flat plug with a controlled normal load. The sample seat surface is manufactured by face turning a tubular part under radial stress and waviness is obtained after elastic relaxation. Modeling is performed on a three-dimensional finite element model of the assembly, composed of the plug, the sample seat, and its holder. The upper sample seat surface, in which topography is recorded by confocal microscopy, is reconstructed using a modal decomposition on the basis of vibrational eigenmodes. Its lower surface, in contact with the holder, is considered as perfectly flat or with its own defects. The contact aperture field between the seat and the plug is computed for a given normal load and is used to solve the incompressible Reynolds equation with a boundary element method, yielding the transmissivity. Predicted transmissivities reveal to be in good agreement with experimental data at low clamping loads and are overestimated for larger ones. Defects on the lower surface of the seat are shown to have a significant impact on the seat-to plug contact transmissivity.

Finite Element Analysis of Nonuniformity of Tires with Imperfections5

2007 ◽  
Vol 35 (3) ◽  
pp. 226-238 ◽  
Author(s):  
K. M. Jeong ◽  
K. W. Kim ◽  
H. G. Beom ◽  
J. U. Park
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Three Dimensional ◽  
Element Model ◽  
Radial Force ◽  
Element Analysis ◽  
The Finite Element Analysis ◽  
Dimensional Finite Element ◽  
Force Variation ◽  
Three Dimensional Finite Element

Abstract The effects of variations in stiffness and geometry on the nonuniformity of tires are investigated by using the finite element analysis. In order to evaluate tire uniformity, a three-dimensional finite element model of the tire with imperfections is developed. This paper considers how imperfections, such as variations in stiffness or geometry and run-out, contribute to detrimental effects on tire nonuniformity. It is found that the radial force variation of a tire with imperfections depends strongly on the geometrical variations of the tire.

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