scholarly journals VERIFICATION OF THE ANALYTICAL MODEL FOR OCEAN WAVE-SOIL-CAISSON INTERACTION

1986 ◽  
Vol 1 (20) ◽  
pp. 154 ◽  
Author(s):  
William G. McDougal ◽  
Yau-Tang Tsai ◽  
Charles K. Sollitt
Keyword(s):  
Finite Element ◽  
Finite Element Model ◽  
Analytical Model ◽  
Large Scale ◽  
Finite Thickness ◽  
Element Model ◽  
State University ◽  
Surface Displacements ◽  
Wave Research ◽  
Oregon State University

An analytical model for wave-soil-caisson interaction is verified by comparison with a finite element model and large scale experimental results. The analytical and finite element model estimates of the stresses and surface displacements of an elastic layer of finite thickness are in good agreement. The physical model experiments were conducted at the O.H. Hinsdale Wave Research Facility at Oregon State University. A 10-ft high, 8-ft long caisson was constructed on a bedding layer overlying 1 to 3 ft of soil. The caisson was exposed to waves with heights of 0.68 to 4.4 ft with periods of 1.77 to 8.80 sec. Experimental and analytical comparisons for porewater pressure were in agreement but the displacements were quite scattered.

scholarly journals Co-Simulation of an Inverter Fed Permanent Magnet Synchronous Machine

2014 ◽  
Vol 6 (1) ◽  
pp. 19-25
Author(s):  
Gergely Máté Kiss ◽  
István Vajda
Keyword(s):  
Finite Element ◽  
Finite Element Model ◽  
Analytical Model ◽  
Element Model ◽  
Electrical Machine ◽  
Permanent Magnet Synchronous Machine ◽  
Variable Speed ◽  
Analytical Variable ◽  
Drive Model ◽  
The Finite Element Model

Abstract Co-simulation is a method which makes it possible to study the electric machine and its drive at once, as one system. By taking into account the actual inverter voltage waveforms in a finite element model instead of using only the fundamental, we are able to study the electrical machine's behavior in more realistic scenario. The recent increase in the use of variable speed drives justifies the research on such simulation techniques. In this paper we present the co-simulation of an inverter fed permanent magnet synchronous machine. The modelling method employs an analytical variable speed drive model and a finite element electrical machine model. By linking the analytical variable speed drive model together with a finite element model the complex simulation model enables the investigation of the electrical machine during actual operation. The methods are coupled via the results. This means that output of the finite element model serves as an input to the analytical model, and the output of the analytical model provides the input of the finite element model for a different simulation, thus enabling the finite element simulation of an inverter fed machine. The resulting speed and torque characteristics from the analytical model and the finite element model show a good agreement. The experiences with the co-simulation technique encourage further research and effort to improve the method.

Modelling of 4H-SiC VJFETs with Self-Aligned Contacts

2016 ◽  
Vol 858 ◽  
pp. 913-916 ◽  
Author(s):  
Konstantinos Zekentes ◽  
Konstantin Vassilevski ◽  
Antonis Stavrinidis ◽  
George Konstantinidis ◽  
Maria Kayambaki ◽  
...  
Keyword(s):  
Finite Element ◽  
Finite Element Model ◽  
Analytical Model ◽  
Element Model ◽  
Experimental Results ◽  
Compact Model ◽  
Channel Lengths ◽  
The Finite Element Model

Purely vertical 4H-SiC JFETs have been modeled by using three different approaches: the analytical model, the finite element model and the compact model. The results of the modeling have been compared with experimental results on a series of fabricated self-aligned devices with two different channel lengths (0.3 and 1.1μm) and various channel widths (1.5, 2, 2.5, 3, 4 and 5 μm). For all the considered models I-V and C-V characteristics could be satisfactorily simulated.

scholarly journals Three-Dimensional Response of the Supported-Deep Excavation System: Case Study of a Large Scale Underground Metro Station

Geosciences ◽  
2020 ◽  
Vol 10 (2) ◽  
pp. 76
Author(s):  
Ashraf Hefny ◽  
Mohamed Ezzat Al-Atroush ◽  
Mai Abualkhair ◽  
Mariam Juma Alnuaimi
Keyword(s):  
Finite Element ◽  
Finite Element Model ◽  
Large Scale ◽  
Three Dimensional ◽  
Element Model ◽  
Two Dimensional ◽  
Deep Excavation ◽  
Metro Station ◽  
Dimensional Finite Element ◽  
Three Dimensional Finite Element

The complexities and the economic computational infeasibility associated in some cases, with three-dimensional finite element models, has imposed a motive for many investigators to accept numerical modeling simplification solutions such as assuming two-dimensional (2D) plane strain conditions in simulation of several supported-deep excavation problems, especially for cases with a relatively high aspect ratio in plan dimensions. In this research, a two-dimensional finite element model was established to simulate the behavior of the supporting system of a large-scale deep excavation utilized in the construction of an underground metro station Rod El Farrag project (Egypt). The essential geotechnical engineering properties of soil layers were calculated using results of in-situ and laboratory tests and empirical correlations with SPT-N values. On the other hand, a three-dimensional finite element model was established with the same parameters adopted in the two-dimensional model. Sufficient sensitivity numerical analyses were performed to make the three-dimensional finite element model economically feasible. Results of the two-dimensional model were compared with those obtained from the field measurements and the three-dimensional numerical model. The comparison results showed that 3D high stiffening at the primary walls’ corners and also at the locations of cross walls has a significant effect on both the lateral wall deformations and the neighboring soil vertical settlement.

scholarly journals Simulation Analysis of a Multiple-Vehicle, High-Speed Train Collision Using a Simplified Model

2018 ◽  
Vol 2018 ◽  
pp. 1-11 ◽  
Author(s):  
Suchao Xie ◽  
Weilin Yang ◽  
Ping Xu
Keyword(s):  
Finite Element ◽  
Finite Element Model ◽  
High Speed ◽  
Large Scale ◽  
Computing Time ◽  
Element Model ◽  
Vehicle Body ◽  
Railway Vehicle ◽  
Storage Space ◽  
High Speed Train

To solve the problems associated with multiple-vehicle simulations of railway vehicles including large scale modelling, long computing time, low analysis efficiency, need for high performance computing, and large storage space, the middle part of the train where no plastic deformation occurs in the vehicle body was simplified using mass and beam elements. Comparative analysis of the collisions between a single railway vehicle (including head and intermediate vehicles before, and after, simplification) and a rigid wall showed that variations in impact kinetic energy, internal energy, and impact force (after simplification) are consistent with those of the unsimplified model. Meanwhile, the finite element model of a whole high-speed train was assembled based on the simplified single-vehicle model. The numbers of nodes and elements in the simplified finite element model of the whole train were 63.4% and 61.6%, respectively, compared to those of the unsimplified model. The simplified whole train model using the above method was more accurate than the multibody model. In comparison to the full-size finite element model, it is more specific, had more rapid computational speed, and saved a large amount of computational power and storage space. Finally, the velocity and acceleration data for every car were discussed through the analysis of the collision between two simplified trains at various speeds.

scholarly journals Clustering of Parameter Sensitivities: Examples from a Helicopter Airframe Model Updating Exercise

2009 ◽  
Vol 16 (1) ◽  
pp. 75-87 ◽  
Author(s):  
H. Shahverdi ◽  
C. Mares ◽  
W. Wang ◽  
J.E. Mottershead
Keyword(s):  
Finite Element ◽  
Finite Element Model ◽  
Large Scale ◽  
Structural Changes ◽  
Model Updating ◽  
Mass Density ◽  
Main Tool ◽  
Element Model ◽  
Sensitivity Matrix ◽  
Comparative Results

The need for high fidelity models in the aerospace industry has become ever more important as increasingly stringent requirements on noise and vibration levels, reliability, maintenance costs etc. come into effect. In this paper, the results of a finite element model updating exercise on a Westland Lynx XZ649 helicopter are presented. For large and complex structures, such as a helicopter airframe, the finite element model represents the main tool for obtaining accurate models which could predict the sensitivities of responses to structural changes and optimisation of the vibration levels. In this study, the eigenvalue sensitivities with respect to Young's modulus and mass density are used in a detailed parameterisation of the structure. A new methodology is developed using an unsupervised learning technique based on similarity clustering of the columns of the sensitivity matrix. An assessment of model updating strategies is given and comparative results for the correction of vibration modes are discussed in detail. The role of the clustering technique in updating large-scale models is emphasised.

Analysis on the Upholding Bracket for Bridge Fabricating System & the Building of its FEM Model

2012 ◽  
Vol 472-475 ◽  
pp. 641-644
Author(s):  
Quan Cai Li ◽  
Cui Rong Wu
Keyword(s):  
Finite Element ◽  
Structural Analysis ◽  
Finite Element Model ◽  
Static Analysis ◽  
Large Scale ◽  
Element Model ◽  
Fem Model ◽  
At Home

Bridge Fabricating System is one of the most widely used large-scale machinery equipment in construction fields like highway, railway both at home and abroad. Through structural analysis on the bridge fabricating system, and build a finite element model with ANSYS, we can form a found- ation for Static Analysis for it.

Fully Coupled Three-Scale Finite Element Model for the Mechanical Response of a New Bio-Inspired Composite

2011 ◽  
Author(s):  
Erick I. Saavedra Flores ◽  
Senthil Murugan ◽  
Michael I. Friswell ◽  
Eduardo A. de Souza Neto
Keyword(s):  
Finite Element ◽  
Magnesium Alloy ◽  
Finite Element Model ◽  
Large Scale ◽  
Mechanical Response ◽  
Volume Fraction ◽  
Element Model ◽  
Crystalline Cellulose ◽  
Gauss Point ◽  
Fully Coupled

This paper proposes a fully coupled three-scale finite element model for the mechanical description of an alumina/magnesium alloy/epoxy composite inspired in the mechanics and architecture of wood cellulose fibres. The constitutive response of the composite (the large scale continuum) is described by means of a representative volume element (RVE, corresponding to the intermediate scale) in which the fibre is represented as a periodic alternation of alumina and magnesium alloy fractions. Furthermore, at a lower scale the overall constitutive behavior of the alumina/magnesium alloy fibre is modelled as a single material defined by a large number of RVEs (the smallest material scale) at the Gauss point (intermediate) level. Numerical material tests show that the choice of the volume fraction of alumina based on those volume fractions of crystalline cellulose found in wood cells results in a maximisation of toughness in the present bio-inspired composite.

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