- Electromagnetic Simulation and Numerical Methods
- Magnetic Properties and Applications
- Non-Destructive Testing Techniques
- Electric Motor Design and Analysis
- Advanced Numerical Methods in Computational Mathematics
- Electromagnetic Scattering and Analysis
- Induction Heating and Inverter Technology
- Numerical methods in engineering
- Vibration and Dynamic Analysis
- Advanced Mathematical Modeling in Engineering
- Composite Material Mechanics
- Magnetic Bearings and Levitation Dynamics
- Advanced MEMS and NEMS Technologies
- Microstructure and Mechanical Properties of Steels
- Advanced Antenna and Metasurface Technologies
- Thermal Analysis in Power Transmission
- High voltage insulation and dielectric phenomena
- Magnetic Field Sensors Techniques
- Electromagnetic Compatibility and Noise Suppression
- Welding Techniques and Residual Stresses
- Composite Structure Analysis and Optimization
- Lightning and Electromagnetic Phenomena
- Ultrasonics and Acoustic Wave Propagation
- Electromagnetic Launch and Propulsion Technology
- Topology Optimization in Engineering
University of Liège
2010-2019
Fund for Scientific Research
2003-2014
Architects Council of Europe
2010
Ghent University
2010
Centre National de la Recherche Scientifique
2008
Institut polytechnique de Grenoble
2008
Science et Ingénierie des Matériaux et Procédés
2008
Université Paris-Sud
2008
Université Grenoble Alpes
2008
University of Udine
2006
A general computer aided description environment for the treatment of discrete problems, based on a concise structure both development and application levels, is described applied to finite element method. Its characteristics reveal its great ability welcome in an evolutive way wide range physical models numerical methods, with any coupling them. It therefore adapted various activities, such as research, collaboration, education, training industrial studies.
Starting from the well known analytical formula for eddy current losses in electrical steel laminations, saturation and edge effects are studied by means of 1D 2D finite element models a single lamination. A novel method directly including laminated core energy dissipation time stepped model complete (rotating) machine is proposed. By way example applied to tooth with enforced flux waveforms.
The authors present a novel nonlinear homogenization technique for laminated iron cores in three-dimensional (3-D) finite-element (FE) models of electromagnetic devices. takes into account the eddy current effects stacked core without need modeling all laminations separately. A constitutive magnetic law is considered. system algebraic equations obtained after time discretization solved by means Newton-Raphson scheme. By way validation, method applied to 3-D FE model ring with toroidal coil
A general approach for the frequency-domain homogenization of multiturn windings in two-dimensional (2-D) finite element (FE) calculations is presented. First, a skin and proximity effect characterization individual conductors, arbitrary cross-section packing, obtained using representative 2-D FE model. Herein, three excitation modes are considered, viz current flux density two perpendicular directions. In practical cases, independent frequency-dependent impedance complex reluctivity tensor...
A method is developed to take the eddy currents in lamination stacks into account with finite-element using three-dimensional (3-D) magnetic vector potential magnetodynamic formulation. It consists converting stacked laminations continuums which terms are associated for considering eddy-current loops produced by both parallel and perpendicular fluxes. Two levels of accuracy proposed. The best one based on an accurate analytical expression makes adapted a wide-frequency range, i.e., even low...
The authors present a novel time-domain homogenization technique for laminated iron cores in three-dimensional (3-D) FE models of electromagnetic devices when using the magnetic vector potential formulation. method is based on polynomial orthogonal decomposition variation induction throughout thickness laminations. nonconstant components, due to skin effect, produce additional degrees freedom and equations homogenized core. Insulating layers finite width between laminations (fill factor <1)...
A method for defining global quantities related to fluxes and circulations is proposed in the frame of finite element method. The definition perfect accordance with discretized weak formulations problems. It therefore enables a natural coupling between local various formulations, while keeping symmetrical matrix system, then open physical Applications are given electrostatics, magnetostatics magnetodynamics.
A generalization of the Whitney complex is proposed, which not now associated with simplices, i.e. tetrahedra in three dimensions, but collections kinds geometric elements: tetrahedra, hexahedra and prisms. Nodal, edge, facet volume finite elements, mixed those are defined. Base functions for approximation relative to these elements defined their properties established. interpretation given.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">></ETX>
In this paper, a novel and easy-to-implement approach to the harmonic-balance finite-element modeling of electromagnetic devices is presented. The governing system nonlinear algebraic equations derived assuming an arbitrary (anisotropic) magnetic constitutive law. It solved by means Newton-Raphson (NR) method, elaboration which very simple thanks introduction differential reluctivity tensor. method validated applying it three-dimensional two-dimensional voltage-driven model three-phase...
The aim of the proposed method is projection an electromagnetic field belonging to a given function space (continuous or not) onto discrete one spanned by finite element basis functions. This technique useful for imposing inhomogeneous boundary conditions volumic source fields, calculating dual primal mesh interpolation.
A procedure is proposed to deal with magnetic vector potential finite element magnetodynamic formulations and the definition of their associated circuit relations, involving voltages currents, especially for massive inductors. It consists in solving two successive problems thanks use edge elements, first problem releasing second one, which useful efficient nonlinear time stepping analyses.
This paper deals with the incorporation of a vector hysteresis model in 2D finite‐element (FE) magnetic field calculations. A previously proposed extension well‐known scalar Jiles‐Atherton is considered. The vectorised shown to have same advantages as one: limited number parameters (which value both models) and ease implementation. classical potential FE formulation adopted. Particular attention paid resolution nonlinear equations by means Newton‐Raphson method. It that application latter...
In this paper, we report progress towards a 3D finite element model for the magnetization of high-temperature superconductor (HTS): suggest method that takes into account power law conductivity and demagnetization effects, while neglecting effects associated with currents are not perpendicular to local magnetic induction. We consider samples subjected uniform field varying linearly time. Their is calculated by means weak formulation in magnetostatic approximation Maxwell equations (A–ϕ...
In this paper, the authors propose an original time-domain extension of frequency-domain homogenization multiturn windings in finite element (FE) models. For winding type hand (e.g., round conductor with hexagonal packing), elementary FE model is used for determining dimensionless frequency and coefficients regarding skin proximity effect. These are readily utilized homogenizing complete device. The method successfully applied to axisymmetric 103-turn inductor. results agree very well those...
This paper deals with the time-domain homogenization of multiturn windings in 3-D finite element (FE) models. An elementary two- dimensional (2-D) FE model allows for global eddy-current characterization winding by means dimensionless frequency and coefficients regarding skin proximity effects. These are used complete device. The method is validated considering an axisymmetric 120-turn inductor which a brute-force 2-D (each turn finely discretized) provides accurate reference solution.
In this paper, we investigate the modeling of ferromagnetic multiscale materials.We propose a computational homogenization technique based on heterogeneous method (HMM) that includes both eddy-current and hysteretic losses at mesoscale.The HMM comprises: 1) macroscale problem captures slow variations overall solution; 2) many mesoscale problems allow to determine constitutive law macroscale.As application example, laminated iron core is considered.
Abstract This paper deals with the use of a Jiles‐Atherton vector hysteresis model included in 2D finite element modeling. The is only valid for isotropic materials. It implemented potential formulation along electric circuit equations to account possible external circuit. Newton‐Raphson algorithm used relaxation procedure, whereby at each iteration, coefficient sought so as minimize Euclidean norm residual nonlinear system equations. We have simulated several numerical examples proposed...
Determining the partial discharge (PD) inception voltage (PDIV) is a key point when designing electrical coils or busbars. In this paper, method making it possible to calculate PDIV as well locate PDs in windings of any shape presented. It based on 2-D finite-element computation using both dual-i.e., scalar and vector potential-electrostatic formulations comparison obtained operating points with Paschen's curve.
Dual magnetodynamic and magnetostatic finite element formulations taking thin conducting magnetic shells into account are proposed. The abstraction of the region is performed by treatment surface terms arising in weak formulations, which discretized with Whitney edge elements.
The treatment of massive and stranded inductors is studied in the frame dual magnetodynamic finite element h- /spl alpha/-formulations. On both sides, edge elements are used source fields defined when needed as mathematical tools to be directly each formulation lead circuit relations for inductors. Simplified expressions proposed. accuracy obtained on local solutions parameters pointed out.
Transformation methods are a very powerful tool in finite element modelling. In many cases, an adequate mapping transforms the problem into easier one or allows advantage to be taken of symmetries. This paper demonstrates that any can handled automatically provided classical vector analysis approach is given up for benefit differential geometry approach. As first example, it shown axisymmetrical problems need no more particular treatment cylindrical coordinates on cartesian ones considered...
A general method to compute source fields in magnetostatics or magnetodynamics is presented for inductors of any shape. That field not the physical one because zero divergence condition satisfied. However, freedom so obtained exploited minimize its support as well reduce CPU time. The use edge finite elements enables rigorous construction. test problem illustrates method.
A method for defining electric global quantities, i.e. currents and voltages, in finite element magnetodynamic H-formulations is presented. It makes use of edge elements, which enables direct definition a strong sense as well exploitation the discrete weak formulation to define voltages natural way, without need any supplementary integral formula. applied massive stranded inductors voltage sources coupling with circuit equations.