scholarly journals Use of 3D-FEM Tools to Improve Loss Allocation in Three-Core Armored Cables

Energies ◽  
2021 ◽  
Vol 14 (9) ◽  
pp. 2434
Author(s):  
Juan Carlos del-Pino-López ◽  
Pedro Cruz-Romero
Keyword(s):  
Complex Geometry ◽  
Element Model ◽  
3D Fem ◽  
Loss Allocation ◽  
Remarkable Improvement ◽  
Electromagnetic Interactions ◽  
Allocation Procedure ◽  
Depth Analysis ◽  
New Formulation ◽  
Analytical Expressions

Loss allocation through analytical expressions in three-core lead-sheathed armored cables is challenging due to the complex geometry of this type of cable, commonly employed in submarine energy transmission systems (involving twisted conductors, sheaths and armor). Most of the expressions of the IEC standard 60287 have not been properly adapted for three-core armored cables, leading to inaccurate values for the different losses, so important efforts are currently devoted to improving them. In this work, an improved ultra-shortened 3D finite element model (FEM) is employed for developing an in-depth analysis of the electromagnetic interactions that take place in 6 real cables, being especially focused on those aspects that are not considered in the IEC standard. As a result, important conclusions are derived regarding the losses in conductors and sheaths, which introduce different corrections for improving the accuracy of the IEC expressions. The new formulation is then employed to propose a simplified experimental armor loss allocation procedure. This is virtually applied through the FEM tool to more than 700 cable configurations, showing a remarkable improvement in the loss allocation over the IEC standard and previous experimental procedures.

Calculation and Analysis of the Forces Created by Halbach Permanent-Magnet Electrodynamic Suspension

2012 ◽  
Vol 229-231 ◽  
pp. 440-443
Author(s):  
Yin Chen ◽  
Kun Lun Zhang
Keyword(s):  
Magnetic Field ◽  
Permanent Magnet ◽  
Element Model ◽  
3D Fem ◽  
3D Finite Element ◽  
Drag Forces ◽  
Analytical Algorithm ◽  
Electrodynamic Suspension ◽  
Analytical Expressions ◽  
The Magnetic Field

This paper researches on the levitation and drag forces of Halbach permanent-magnet electrodynamic suspension. First, construct an analytical model to calculate the magnetic field in the air gap and the current in the secondary conductor plate, thus deducing analytical expressions of the levitation and drag forces. Second, establish a 2D and a 3D finite element model, using ANSYS. Finally, at different speeds, from 0 to 250 km/h, compare the forces calculating results through the above three methods. Results generating from the 2D-FEM and the analytical algorithm have less than 3% of relative error, but for having not taken the horizontal components of eddy current in the reaction plate into consideration, thus 10% more than the 3D-FEM calculating results.

A SIMPLIFIED ANALYTICAL PROCEDURE FOR SEISMIC ANALYSIS OF TIMBER LIGHT-FRAME SHEAR WALLS

2019 ◽  
Vol 3 (Special Issue on First SACEE'19) ◽  
pp. 173-180
Author(s):  
Giorgia Di Gangi ◽  
Giorgio Monti ◽  
Giuseppe Quaranta ◽  
Marco Vailati ◽  
Cristoforo Demartino
Keyword(s):  
Analytical Procedure ◽  
Seismic Analysis ◽  
Shear Walls ◽  
Element Model ◽  
Sensitivity Analyses ◽  
Width Ratio ◽  
Damping Factor ◽  
Equivalent Viscous Damping ◽  
Design Variables ◽  
Depth Analysis

The seismic performance of timber light-frame shear walls is investigated in this paper with a focus on energy dissipation and ductility ensured by sheathing-to-framing connections. An original parametric finite element model has been developed in order to perform sensitivity analyses. The model considers the design variables affecting the racking load-carrying capacity of the wall. These variables include aspect ratio (height-to-width ratio), fastener spacing, number of vertical studs and framing elements cross-section size. A failure criterion has been defined based on the observation of both the global behaviour of the wall and local behaviour of fasteners in order to identify the ultimate displacement of the wall. The equivalent viscous damping has been numerically assessed by estimating the damping factor which is in use in the capacity spectrum method. Finally, an in-depth analysis of the results obtained from the sensitivity analyses led to the development of a simplified analytical procedure which is able to predict the capacity curve of a timber light-frame shear wall.

scholarly journals Analysis of AC Transport Loss in Conductor on Round Core Cables

2021 ◽  
Author(s):  
Jiabin Yang ◽  
Chao Li ◽  
Mengyuan Tian ◽  
Shuyu Liu ◽  
Boyang Shen ◽  
...  
Keyword(s):  
Eddy Current ◽  
Complex Geometry ◽  
Layer Structure ◽  
Single Layer ◽  
Element Model ◽  
Structure Design ◽  
Ac Loss ◽  
Shielding Effect ◽  
Transport Loss ◽  
Electro Magnetic

AbstractThe conductor on round core (CORC) cable wound with second-generation high-temperature superconducting (HTS) tapes is a promising cable candidate with superiority in current capacity and mechanical strength. The composing superconductors and the former are tightly assembled, resulting in a strong electro-magnetic interaction between them. Correspondingly, the AC loss is influenced by the cable structure. In this paper, a 3D finite-element model of the CORC cable is first built, and it includes the complex geometry, the angular dependence of critical current and the periodic settings. The modelling is verified by the measurements conducted for the transport loss of a two-layer CORC cable. Subsequently, the simulated results show that the primary transport loss shifts from the former to the superconductors as the current increases. Meanwhile, the loss exhibited in the outer layer is larger than that of the inner layer, which is caused by the shielding effect among layers and the former. This also leads to the current inhomogeneity in CORC cables. In contrast with the two-layer case, the simulated single-layer structure indicates stronger frequency dependence because the eddy current loss in the copper former is always dominant without the cancellation of the opposite-wound layers. The core eddy current of the single structure is denser on the outer surface. Finally, the AC transport losses among a straight HTS tape, a two-layer cable and a single-layer cable are compared. The two-layer structure is confirmed to minimise the loss, meaning an even-numbered arrangement makes better use of the cable space and superconducting materials. Having illustrated the electro-magnetic behaviour inside the CORC cable, this work is an essential reference for the structure design of CORC cables.

3D FEM-NEM Material Joining Simulation in Porthole Die Extrusion

2011 ◽  
Vol 491 ◽  
pp. 151-158 ◽  
Author(s):  
Francesco Gagliardi ◽  
I. Alfaro ◽  
Luigino Filice ◽  
E. Cueto
Keyword(s):  
Finite Element ◽  
Complex Geometry ◽  
Experimental Investigations ◽  
3D Analysis ◽  
3D Fem ◽  
Positive Effects ◽  
Tube Extrusion ◽  
Porthole Die ◽  
Die Extrusion ◽  
Porthole Die Extrusion

The conventional tube extrusion process has been substituted by porthole die extrusion due to relevant advantages in terms of productivity and quality. However, the porthole die has a complex geometry to be effectively designed; consequently, several studies can be found out in the technical literature based on experimental and finite element analyses of the process. From this point of view, while the experimental investigations entail cost and time increasing, due to the die building complexity, finite element techniques present some drawbacks such as the difficulty to simulate material joining and the loss of accuracy due to the heavy mesh distortion and related remeshing. Therefore, the introduction of new numerical techniques for the analyses of this process could have positive effects. In this paper, the Natural Element Method (NEM) together to the alpha shapes and some extra numerical procedures are used in the simulation of tube extrusion, focusing the attention on the simulation of the welding line in a fully 3D analysis. The obtained results are compared with the finite element and experimental ones, measuring the accuracy of the proposed methodology.

A Comparative Study of the Human Body Finite Element Model Under Blast Loadings

2012 ◽  
Author(s):  
X. G. Tan ◽  
R. Kannan ◽  
Andrzej J. Przekwas
Keyword(s):  
Finite Element ◽  
Finite Element Model ◽  
Human Body ◽  
Material Properties ◽  
Complex Geometry ◽  
Blast Loading ◽  
Element Model ◽  
Stress Wave Propagation ◽  
Brain Response ◽  
Time Step

Until today the modeling of human body biomechanics poses many great challenges because of the complex geometry and the substantial heterogeneity of human body. We developed a detailed human body finite element model in which the human body is represented realistically in both the geometry and the material properties. The model includes the detailed head (face, skull, brain, and spinal cord), the skeleton, and air cavities (including the lung). Hence it can be used to accurately acquire the stress wave propagation in the human body under various loading conditions. The blast loading on the human surface was generated from the simulated C4 blast explosions, via a novel combination of 1-D and 3-D numerical formulations. We used the explicit finite element solver in the multi-physics code CoBi for the human body biomechanics. This is capable of solving the resulting large system containing millions of unknowns in an extremely scalable fashion. The meshes generated for these simulations are of good quality. This enables us to employ relatively large time step sizes, without resorting to the artificial time scaling treatment. In order to study the human body dynamic response under the blast loading, we also developed an interface to apply the blast pressure loading on the external human body surface. These newly developed models were used to conduct parametric simulations to find out the brain biomechanical response when the blasts impact the human body. Under the same blast loading we also show the differences of brain response when having different material properties for the skeleton, the existence of other body parts such as torso.

scholarly journals Analysis and Control of Twist Defects of Aluminum Profiles with Large Z-Section in Roll Bending Process

Metals ◽  
2019 ◽  
Vol 10 (1) ◽  
pp. 31 ◽  
Author(s):  
Anheng Wang ◽  
Hongqian Xue ◽  
Emin Bayraktar ◽  
Yanli Yang ◽  
Shah Saud ◽  
...  
Keyword(s):  
Finite Element ◽  
Aluminum Alloy ◽  
Element Model ◽  
Effective Control ◽  
Curvature Radius ◽  
3D Fem ◽  
Fe Method ◽  
Element Analysis ◽  
Roll Bending ◽  
Bending Process

This paper focuses on the twist defects and the control strategy in the process of four-roll bending for aluminum alloy Z-section profiles with large cross-section. A 3D finite element model (3D-FEM) of roll bending process has been developed, on the premise of the curvature radius of the profile, the particularly pronounced twist defects characteristic of 7075-O aluminum alloy Z-section profiles were studied by FE method. The simulation results showed that the effective control of the twist defects of the profile could be realized by adjusting the side roller so that the exit guide roll was higher than the entrance one (the side rolls presented an asymmetric loading mode with respect to the main rolls) and increasing the radius of upper roll. Corresponding experimental tests were carried out to verify the accuracy of the numerical analysis. The experimental results indicated that control strategies based on finite element analysis (FEA) had a significant inhibitory function on twist defects in the actual roll bending process.

INVESTIGATION OF HEAD-DISK INTERFACE AND UNLOADING PROCESS IN HDD WITH AN EFFICIENT SCHEME

2012 ◽  
Vol 19 ◽  
pp. 311-319
Author(s):  
HEJUN DU ◽  
YAN LIU
Keyword(s):  
Hard Disk Drives ◽  
Element Model ◽  
Disk Drives ◽  
Disk Interface ◽  
Efficient Scheme ◽  
Suspension Stiffness ◽  
Suspension Model ◽  
Micrometer Scale ◽  
Parameter Values ◽  
Analytical Expressions

An efficient scheme was developed to analyze head-disk interfaces (HDIs) in hard disk drives. HDIs were studied by decoupling the nanometer scale variations of the air bearings and the micrometer scale changes of the suspensions. The nonlinear variations of the air bearing forces and moments were described with analytical expressions obtained from a surface fitting scheme. Combined with a 3 degree of freedom (DOF) suspension model whose parameters were estimated from a comprehensive finite element model, the historical behaviors of a subambient slider during an unloading process can be obtained in a very short computation period, thus providing a way of exploring a large number of parameter values of the suspension stiffness matrix.

Mechanical response of a panel section with a hexagonally tessellated stiffener grid

2016 ◽  
Vol 231 (8) ◽  
pp. 1402-1414
Author(s):  
M Bouazizi ◽  
T Lazghab ◽  
M Soula
Keyword(s):  
Finite Element ◽  
Finite Element Model ◽  
Mechanical Response ◽  
Element Model ◽  
External Loading ◽  
Original Structure ◽  
Hexagonal Grid ◽  
Aircraft Fuselage ◽  
Stiffened Shells ◽  
Analytical Expressions

Stringers are stiffening members of pressurized aircraft fuselage. They provide support to the fuselage’s skin. A new stringer grid concept is proposed for conventional aircraft fuselage. Optimization is used to find the hexagonal grid that best replaces the original while keeping the same total stringer length. A finite element model is built to analyze the optimal hexagonal grid stiffened structure and compare it with the original orthogonally stiffened structure in terms of eigenfrequencies and static response to external loading. The finite element model is validated through Flugge’s analytical expressions for stiffened shells. Results show that the hexagonal grid stiffened structure yields higher eigenfrequencies with stresses and displacements comparable with that of the original structure.

3D Fem Study of Fluid Flow in the Mould for Billet Continuous Casting

2009 ◽  
Vol 79-82 ◽  
pp. 1269-1272
Author(s):  
Wei Chen ◽  
Bao Xiang Wang ◽  
Yu Zhu Zhang ◽  
Jin Hong Ma ◽  
Su Juan Yuan
Keyword(s):  
Fluid Flow ◽  
Continuous Casting ◽  
Casting Speed ◽  
Three Dimensional ◽  
Casting Process ◽  
Element Model ◽  
3D Fem ◽  
Billet Continuous Casting ◽  
Dimensional Finite Element ◽  
Three Dimensional Finite Element

In this paper, a three-dimensional finite element model is developed to simulate and analyze the turbulent flow in the mould of billet continuous casting. The result shows that if the SEN is used in the continuous casting process, there exists a symmetrical stronger vortex in the middle of the mould and a weaker vortex above the nozzle. The casting speed, the depth and diameter of SEN all have significant effect on the fluid flow field and the turbulent kinetic energy on the meniscus, and then have effect on the billet quality. At the given conditions, the optimum set of parameters is: the casting speed 0.035 , the depth of the SEN 0.1 , the diameter of the SEN 0.025 . Online verifying of this model has been developed, which can be proved that it is very useful to control the steel quality and improve the productivity.

Sign in / Sign up

Export Citation Format

Share Document