scholarly journals Seismic behaviour of a large-scale concrete-block retaining wall

2019 ◽  
Vol 92 ◽  
pp. 16007
Author(s):  
Noboru Sato ◽  
Toshikazu Sawamatsu ◽  
Takehiko Nitta ◽  
Hiroaki Miyatake ◽  
Kazuhito Kondo
Keyword(s):  
Finite Element ◽  
Seismic Response ◽  
Large Scale ◽  
Retaining Wall ◽  
Fem Simulation ◽  
Concrete Block ◽  
Scale Model ◽  
Seismic Behaviour ◽  
Experimental Conditions ◽  
Concrete Blocks

In this study, an inclined model experiment and finite element analyses were conducted to evaluate the failure mode and seismic response of a dry-type large-scale concrete-block retaining wall (LCBW). In the experiment, the objective was to reproduce the sliding between concrete blocks that was observed in past cases LCBW damage in order to characterise the behaviour until failure. A numerical simulation corresponding to the experimental conditions was conducted by the finite element method (FEM). Dynamic analyses were also performed by FEM to investigate the seismic response of the concrete blocks under various ground conditions. The experimental results revealed that slip between the concrete blocks caused brittle failure of the LCBW. In the FEM simulation, the joint elements reproduced the experimentally observed sliding between the concrete blocks. A dynamic simulation of the full-scale model revealed that significant sliding and rocking of the concrete block occur in a dry-type LCBW. These findings indicate that stress concentration may occur at the heels of the concrete blocks during an earthquake.

scholarly journals Stator Non-Uniform Radial Ventilation Design Methodology for a 15 MW Turbo-Synchronous Generator Based on Single Ventilation Duct Subsystem

Energies ◽  
2021 ◽  
Vol 14 (10) ◽  
pp. 2760
Author(s):  
Ruiye Li ◽  
Peng Cheng ◽  
Hai Lan ◽  
Weili Li ◽  
David Gerada ◽  
...  
Keyword(s):  
Finite Element ◽  
Temperature Distribution ◽  
Design Methodology ◽  
Large Scale ◽  
Synchronous Generator ◽  
Axial Direction ◽  
Scale Model ◽  
Element Analysis ◽  
Axial Temperature ◽  
Ventilation Duct

Within large turboalternators, the excessive local temperatures and spatially distributed temperature differences can accelerate the deterioration of electrical insulation as well as lead to deformation of components, which may cause major machine malfunctions. In order to homogenise the stator axial temperature distribution whilst reducing the maximum stator temperature, this paper presents a novel non-uniform radial ventilation ducts design methodology. To reduce the huge computational costs resulting from the large-scale model, the stator is decomposed into several single ventilation duct subsystems (SVDSs) along the axial direction, with each SVDS connected in series with the medium of the air gap flow rate. The calculation of electromagnetic and thermal performances within SVDS are completed by finite element method (FEM) and computational fluid dynamics (CFD), respectively. To improve the optimization efficiency, the radial basis function neural network (RBFNN) model is employed to approximate the finite element analysis, while the novel isometric sampling method (ISM) is designed to trade off the cost and accuracy of the process. It is found that the proposed methodology can provide optimal design schemes of SVDS with uniform axial temperature distribution, and the needed computation cost is markedly reduced. Finally, results based on a 15 MW turboalternator show that the peak temperature can be reduced by 7.3 ∘C (6.4%). The proposed methodology can be applied for the design and optimisation of electromagnetic-thermal coupling of other electrical machines with long axial dimensions.

Three-Dimensional FEM Simulation of the Ship-Bridge Collision

2013 ◽  
Vol 405-408 ◽  
pp. 3243-3247
Author(s):  
Wei Su ◽  
Ying Sun ◽  
Shi Qing Huang ◽  
Ren Huai Liu
Keyword(s):  
Finite Element ◽  
Boundary Conditions ◽  
Reference Values ◽  
Large Scale ◽  
Three Dimensional ◽  
Fem Simulation ◽  
Structural Safety ◽  
Fem Model ◽  
Finite Element Software

In this paper, the structural safety of the Niuwan Bridge subjected to vessel collision is investigated by the large-scale commercial finite element software ANSYS. A whole FEM model is built and a reasonable analysis and illustration for taking the value of vessel-collision forces is presented. Additionally, under the premise of reasonable simulation of the boundary conditions, the effects of the support abutments, the prestress and the carloads are considered. The analysis results have certain reference values for the anti-collision and reinforcement of bridges.

Seismic Responses of Large Flexible Structure Including Contact Problem

1999 ◽  
Author(s):  
Hiroshi Kuribara ◽  
Nobuyuki Kobayashi
Keyword(s):  
Contact Problem ◽  
Seismic Response ◽  
Large Scale ◽  
Flexible Structures ◽  
Modeling Method ◽  
Scale Model ◽  
Nonlinear Seismic Response ◽  
Container Crane ◽  
Contact Configuration ◽  
Large Scale Model

Abstract A modeling method for the seismic response of large movable flexible structures including the contact problem between wheels attached at the bottom ends of the structure and a rail, such as a container crane and an unloader, is developed. The contact configuration and the contact force between the wheel attached at the structure and the ground, that significantly affect to the seismic response of the structure, are classified and calculated according to geometric relationships between contact judging markers defined on the wheel and the rail. From the numerical simulation using proposed method, it is clarified that the presented modeling method simulates quite well the nonlinear seismic response of the container crane including the uplifting and derailment behavior of the wheel that is obtained by results of the large scale model shaking tests.

scholarly journals Seismic Behaviour of Buried Pipelines: 3D Finite Element Approach

2014 ◽  
Vol 2014 ◽  
pp. 1-9 ◽  
Author(s):  
Smrutirekha Sahoo ◽  
Bappaditya Manna ◽  
K. G. Sharma
Keyword(s):  
Finite Element ◽  
Seismic Response ◽  
Ground Deformation ◽  
Seismic Wave Propagation ◽  
Pipe Diameter ◽  
Bend Angle ◽  
Burial Depth ◽  
Maximum Magnitude ◽  
Buried Pipelines ◽  
Seismic Behaviour

This paper presents a numerical investigation on six pipeline models to study the seismic response of single and double buried pipelines using finite element method. Different depth and spacing of pipes are considered to investigate their prominent role in the seismic response of buried pipelines under an earthquake loading having PGA of 0.2468 g. In case of single pipeline, the maximum magnitude of final displacement as well as the stress at the end of the seismic sequence is found at the burial depth equal to the pipe diameter. In case of double pipeline, the maximum magnitude of final displacement is found when the spacing between pipes is equal to half the pipe diameter and there is an increasing tendency of developed stress with increase in spacing between pipes. In addition to the above results, the response of the buried pipelines with a particular bend angle (artificially induced bend/buckle) to the permanent ground deformation which is assumed to be the result of seismic wave propagation has also been studied. Remarkable differences in these results are obtained and with these results the designers can reduce seismic risk to their buried pipelines by taking proper precautionary measures.

A Distributed Computing Tool for Generating Neural Simulation Databases

2006 ◽  
Vol 18 (12) ◽  
pp. 2923-2927 ◽  
Author(s):  
Robert J. Calin-Jageman ◽  
Paul S. Katz
Keyword(s):  
High Performance ◽  
Large Scale ◽  
Model Neuron ◽  
Scale Model ◽  
Large Set ◽  
Experimental Conditions ◽  
Entry Level ◽  
Neural Simulation ◽  
Wide Range ◽  
Parameter Values

After developing a model neuron or network, it is important to systematically explore its behavior across a wide range of parameter values or experimental conditions, or both. However, compiling a very large set of simulation runs is challenging because it typically requires both access to and expertise with high-performance computing facilities. To lower the barrier for large-scale model analysis, we have developed NeuronPM, a client/server application that creates a “screen-saver” cluster for running simulations in NEURON (Hines & Carnevale, 1997). NeuronPM provides a user-friendly way to use existing computing resources to catalog the performance of a neural simulation across a wide range of parameter values and experimental conditions. The NeuronPM client is a Windows-based screen saver, and the NeuronPM server can be hosted on any Apache/PHP/MySQL server. During idle time, the client retrieves model files and work assignments from the server, invokes NEURON to run the simulation, and returns results to the server. Administrative panels make it simple to upload model files, define the parameters and conditions to vary, and then monitor client status and work progress. NeuronPM is open-source freeware and is available for download at http://neuronpm.homeip.net . It is a useful entry-level tool for systematically analyzing complex neuron and network simulations.

Ultraprecision Glass Molding Press for Microgrooves with Different Pitch Sizes

2013 ◽  
Vol 7 (6) ◽  
pp. 678-685 ◽  
Author(s):  
Ryuichi Kobayashi ◽  
◽  
Tianfeng Zhou ◽  
Keita Shimada ◽  
Masayoshi Mizutani ◽  
...  
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Glass Surface ◽  
Fem Simulation ◽  
Experimental Results ◽  
Experimental Conditions ◽  
Glass Molding ◽  
Periodic Microstructures ◽  
Simulation Results ◽  
Efficient Manufacturing

Glass molding press is an efficient manufacturing technology to fabricate microstructures on glass. To optimize the experimental conditions for precision replication of periodic microstructures with different pitch sizes, Finite Element Method (FEM) simulation and experiments were carried out to study the glass molding press process. First, the effects of the change in pitch size on stress and geometrical replicating accuracy were evaluated. Thereafter, glass molding experiments were carried out to form microstructures on the glass surface, and the molded microstructures were measured. By comparing the simulation results with experimental results, the FEM simulation was experimentally verified, and the optimal machining conditions were obtained and discussed.

Nonlinear Seismic Responses of Container Cranes Including the Contact Problem Between Wheels and Rails

2004 ◽  
Vol 126 (1) ◽  
pp. 59-65 ◽  
Author(s):  
Nobuyuki Kobayashi ◽  
Hiroshi Kuribara ◽  
Tomokazu Honda ◽  
Masahiro Watanabe
Keyword(s):  
Contact Problem ◽  
Seismic Response ◽  
Large Scale ◽  
Three Dimensional ◽  
Modeling Method ◽  
Contact Forces ◽  
Scale Model ◽  
Container Cranes ◽  
Nonlinear Seismic Response ◽  
Container Crane

This paper presents a modeling method based on multibody dynamics formulation for simulating the three-dimensional nonlinear seismic response of a large, movable container crane, including the contact problem regarding the wheels attached to the bottom of its legs and the rails on which they ride. As a container crane is large and flexible structure, its wheels should be lifted up and derailed due to the seismic excitation. The contact configuration and the contact forces between the wheels and the rail or the ground that significantly affect the seismic response of the structure are classified and calculated in reference to geometric relationships between contact-judging markers on the wheels and the rails. It is found that the numerical simulations with the presented modeling method quite accurately simulates the nonlinear seismic response of a container crane including the uplifting and derailment behavior of the wheels that is found in large-scale model shaking tests.

scholarly journals TIME SCALE FOR MODELING BEACH CHANGE

1986 ◽  
Vol 1 (20) ◽  
pp. 88 ◽  
Author(s):  
Masahiro Ito ◽  
Yoshito Tsuchiya
Keyword(s):  
Time Scale ◽  
Large Scale ◽  
Shoreline Change ◽  
Scale Model ◽  
Experimental Conditions ◽  
Equilibrium Beach Profile ◽  
Beach Processes ◽  
Allowable Range ◽  
Set Up ◽  
Relationship Of

A time scale in the similarity of beach change between model and prototype in transitional beach processes from an initial even slope to an equilibrium is developed using a series of small- and large-scale experiments in which the experimental conditions were set up with the scale-model relationship by the authors (1984). The time scale is obtained empirically as a function of experimental scale. Applied the proposed time scale and the scale-model relationship to model experiments, similarity of morphological beach change such as shoreline change and relative breaker point was well reproduced within the allowable range of experimental error. A semi-theoretical time scale is obtained from the continuity equation, the sediment transport rate, and the scale-model relationship of equilibrium beach profile in two-dimensional beach change. The relation between experimental and semi-theoretical time scale is discussed.

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