References of "Boman, Romain"
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See detailImage-based Finite Element Mesh Generation for Microstructures
D'Otreppe, Vinciane ULg; Mengoni, Marlène ULg; Boman, Romain ULg et al

Conference (2011, November 14)

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See detailComparison of Data Transfer Methods between Meshes in the Frame of the Arbitrary Lagrangian Eulerien Formalism
Bussetta, Philippe ULg; Boman, Romain ULg; Ponthot, Jean-Philippe ULg

in Proceedings of "Fifth International Conference on Advanced COmputationalMethods in ENgineering" (2011, November)

In nonlinear solid Mechanics, the Arbitrary Lagrangian Eulerian (ALE) formalism is a common way to avoid mesh distortion when very large deformations occur in the modelled process. Usually, the ALE ... [more ▼]

In nonlinear solid Mechanics, the Arbitrary Lagrangian Eulerian (ALE) formalism is a common way to avoid mesh distortion when very large deformations occur in the modelled process. Usually, the ALE resolution procedure is based on an “operator split”, the second part of which is a Data Transfer between two meshes sharing the same topology (same number of nodes and same number of element neighbours for each of them). Thanks to this interesting property, classical ALE transfer algorithms can bemuchmore optimised in terms of CPU time than the ones that are used in the frame of a complete remeshing. However, the resulting CPU-efficient transfer schemes suffer from two main drawbacks. The first one is a spurious crosswind diffusion coming from the corner fluxes that have been neglected. The second issue is the number of explicit transfer steps which may become very large when the element size decreases. In this paper, these classical ALE Data Transfer methods are compared to more general algorithms which do not make any assumption on the topology of both meshes. [less ▲]

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See detailEffects of the roll forming process on the mechanical properties of thin-walled sections made of non linear metallic materials
Rossi, Barbara ULg; Boman, Romain ULg; Degée, Hervé ULg

in Proceedings of the 6th International Conference on Thin Walled Structures: ICTWS2011, Timisoara 5-7 September 2011 (2011, September 05)

It is well known that the cold-forming process is likely to significantly enhance the mechanical properties of the profile by strain hardening leading to increased resistance compared to a resistance ... [more ▼]

It is well known that the cold-forming process is likely to significantly enhance the mechanical properties of the profile by strain hardening leading to increased resistance compared to a resistance assessment based on nominal properties. It is thus necessary to accurately determine the mechanical properties after the cold process of fabrication. The knowledge on these enhanced properties is rather good for profiles made of traditional construction steel (carbon steel with yield strength between 200 and 400 MPa) characterized by an elasticplastic behaviour. However less information is available for profiles made of materials exhibiting a non linear stress-strain relationship. In this context, the paper presents a parametric study on roll-profiled channel sections. For that purpose, the finite element code METAFOR developed at the LTAS division of the University of Liège is used to simulate the forming process of profiles made of high strength steel and of stainless steel. In the simulations, different values of the radius to thickness ratio of the corners are considered. The results of the numerical simulations are expressed in terms of resulting proof strength in the corners versus the radius to thickness ratio for the different materials. They are finally compared to existing predictive formulations. Additional considerations are also given on the forming process itself (i.e. on the configuration of the rolls or on the springback). [less ▲]

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See detailNumerical Simulation of Stationary Roll Forming using ALE formalism
Boman, Romain ULg; Ponthot, Jean-Philippe ULg

in Oñate, E.; Owen, D. R. J.; Peric, D. (Eds.) et al Computational Plasticity XI - Fundamentals and Applications (2011, September)

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See detailMETALUB – A Slab Method Software for the Numerical Simulation of Mixed Lubrication Regime in Cold Strip Rolling
Carretta, Yves ULg; Boman, Romain ULg; Stephany, Antoine et al

in Proceedings of the Institution of Mechanical Engineers - Part J - Journal of Engineering Tribology (2011), 225(9), 894-904

A cold rolling model taking into account mixed lubrication regime has been developed and included into a simulation software named MetaLub. The main objective is to enhance the performances of rolling ... [more ▼]

A cold rolling model taking into account mixed lubrication regime has been developed and included into a simulation software named MetaLub. The main objective is to enhance the performances of rolling mills from a lubrication point of view. It means that lubricant rheology but also roll diameters and roughness, etc., can be optimised to improve stability and efficiency of the rolling tool. The main features of MetaLub, are briefly presented in this paper. Then, two studies of the influence of rolling speed and negative forward slip are discussed. The obtained numerical results are presented and compared to some experimental data from literature and from ArcelorMittal facilities in order to validate the model and to show its capacity to understand and help to improve industrial rolling conditions. [less ▲]

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See detailInfluence of thermoelectric coupling on pacemaker activity generated by mechano-electric feedback in a one-dimensional ring-shaped model of cardiac fiber
Collet, Arnaud ULg; Desaive, Thomas ULg; Pierard, Luc ULg et al

in XXIIIrd congress of the International Society of Biomechanics, July 3-7, 2011 (2011, July 05)

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See detailInfluence of thermoelectric coupling on pacemaker activity generated by mechano-electric feedback in a one-dimensional ring-shaped model of cardiac fiber
Collet, Arnaud ULg; Desaive, Thomas ULg; Pierard, Luc ULg et al

Poster (2011, July 05)

Recently, the influence of thermal processes on electrophysiology has clearly been underlined, using a FitzHugh–Nagumo-type (FHN-type) model. When the temperature is raised, the action potential duration ... [more ▼]

Recently, the influence of thermal processes on electrophysiology has clearly been underlined, using a FitzHugh–Nagumo-type (FHN-type) model. When the temperature is raised, the action potential duration (APD) has been shown to shorten, while the action potential (AP) amplitude decreases, and the conduction velocity increases. In the present study, we investigate the effects of thermoelectric coupling on mechano-electric feedback (MEF), and more specifically, on pacemaker activity generated by MEF. To investigate these effects, thermoelectric coupling is introduced in a one-dimensional ring-shaped electromechanical model of cardiac fiber, which takes into account excitation-contraction coupling (ECC), as well as MEF. [less ▲]

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See detailDamage and Fracture of Materials Submitted to High Strain Rates. A Thermomechanically Implicit Coupled Approach with Element Erosion
Jeunechamps, Pierre-Paul; Boman, Romain ULg; Papeleux, Luc ULg et al

in Proceedings of the 3rd International Conference on Impact Loading of Lightweight Structures (2011, June 28)

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See detailInfluence of thermoelectric coupling on pacemaker activity generated by mechano-electric feedback in a one-dimensional ring-shaped model of cardiac fiber
Collet, Arnaud ULg; Desaive, Thomas ULg; Pierard, Luc ULg et al

Poster (2011, June 01)

The mechano-electric feedback (MEF) in the heart consists in the influence of the tissue deformations on the cardiac electrical activity. Under certain conditions, tissue deformations can generate ... [more ▼]

The mechano-electric feedback (MEF) in the heart consists in the influence of the tissue deformations on the cardiac electrical activity. Under certain conditions, tissue deformations can generate electrical perturbations via stretch-activated channels, such that the membrane potential can exceed the threshold value needed in order to trigger cardiac action potentials (APs). In the present study, we have developed a one-dimensional ring-shaped model of cardiac fiber taking into account three different couplings: the excitation-contraction coupling (ECC), the MEF and the thermoelectric coupling (TEC). The main goal of this work is to examine the effects of the TEC on the different properties of the pacemaker activity generated by the MEF. [less ▲]

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See detailThermomechanical simulation of roll forming process based on the coupling of two independent solvers
Carretta, Yves ULg; Boman, Romain ULg; Stephany, Antoine et al

in Proceedings of the IV International Conference on Computational Methods for Coupled Problems in Science and Engineering COUPLED PROBLEMS 2011 (2011, June)

This paper deals with an industrial application of a coupling procedure involving two different computer programs : MetaLub and ThermRoll. The first one models the mechanical phenomena occurring in the ... [more ▼]

This paper deals with an industrial application of a coupling procedure involving two different computer programs : MetaLub and ThermRoll. The first one models the mechanical phenomena occurring in the roll-bite during cold rolling such as elasto-plastic strip strains, elastic-roll deformations, asperity flattening and lubricant flow. The second one uses the previous results to compute the steady-state temperature field of the work-roll and the strip. These two codes are briefly described and a model of an industrial stand demonstrates the importance of the thermomechanical coupling in order to get a better understanding of the process. [less ▲]

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See detailGenerating smooth surface meshes from labelled medical datasets
D'Otreppe, Vinciane ULg; Boman, Romain ULg; Ponthot, Jean-Philippe ULg

in Nithiarasu, Perumal; Löhner, Rainald; van Loon, Raoul (Eds.) et al CMBE11: 2nd International Conference on Computational & Mathematical Biomedical Engineering, 30 March - 1 April, 2011, Washington D.C. U.S.A. (2011, March 30)

In this article, an innovative procedure to create high quality triangular meshes from medical scans is proposed. The approach is based on an enhanced Marching Tetrahedra algorithm that extracts a ... [more ▼]

In this article, an innovative procedure to create high quality triangular meshes from medical scans is proposed. The approach is based on an enhanced Marching Tetrahedra algorithm that extracts a consistent multiple region surface mesh from a labelled volume data set; coupled with a surface reconstruction method to avoid typical staircase artifacts. Mesh smoothing and decimation algorithms are also revised to conform to the multiple material nature of the system as well as to adhere to the underlying volume data. The proposed method is well suited for subsequent volume mesh generation and finite element simulations. [less ▲]

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See detailContinuous Roll Forming Simulation using Arbitrary Lagrangian Eulerian Formalism
Boman, Romain ULg; Ponthot, Jean-Philippe ULg

in Key Engineering Materials [=KEM] (2011), 473

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See detailApplication of the Arbitrary Lagrangian Eulerian Formalism to Stationary Roll Forming Simulations
Boman, Romain ULg; Ponthot, Jean-Philippe ULg

in Advanced Materials Research (2011), 189-193

Due to the length of the mill, accurate modelling of stationary solution of continuous cold roll forming by the finite element method using the classical Lagrangian formulation usually requires a very ... [more ▼]

Due to the length of the mill, accurate modelling of stationary solution of continuous cold roll forming by the finite element method using the classical Lagrangian formulation usually requires a very large mesh leading to huge CPU times. In order to model industrial forming lines including many tools in a reasonable time, the sheet has to be shortened or the element size has to be increased leading to inaccurate results. On top of this, applying loads and boundary conditions on this smaller sheet is usually more difficult than in the continuous case. Moreover, transient dynamic vibrations, which are unnecessarily computed, may appear when the sheet hits each tool, decreasing the convergence rate of the numerical simulation. Beside this classical Lagrangian approach, an alternative method is given by the Arbitrary Lagrangian Eulerian (ALE) formalism which consists in decoupling the motion of the material and the mesh. Starting from an initial guess of the sheet geometry between the rolls, the numerical simulation is performed until the stationary state is reached with a mesh, the nodes of which are fixed in the rolling direction but are free to move on perpendicular plane, following the geometrical boundary of the sheet. The whole forming line can then be modelled using a limited number of brick and contact elements because the mesh is only refined near the tools where bending and contact occur. In this paper, ALE results are compared to previous Lagrangian simulations and experimental measurement on a U-channel, including springback. [less ▲]

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See detailAdvances in Metal Forming Simulation of using Arbitrary Lagrangian Eulerian Formalism
Ponthot, Jean-Philippe ULg; Boman, Romain ULg

in Khan, Akhtar; Meredith, C.; Farrokh, B. (Eds.) Macro to Nano-scale Inelastic Deformation and Failure of Materials & Multi-scale Modeling : Proceedings of PLASTICITY'11, Seventeenth International Symposium on Plasticity and its Current Applications (2011, January)

Accurate modelling of stationary solution of continuous cold roll forming by the finite element method using the classical Lagrangian formulation usually requires a very large mesh leading to huge CPU ... [more ▼]

Accurate modelling of stationary solution of continuous cold roll forming by the finite element method using the classical Lagrangian formulation usually requires a very large mesh leading to huge CPU times. An alternative method is given by the Arbitrary Lagrangian Eulerian (ALE) formalism which consists in decoupling the motion of the material and the mesh. Starting from an initial guess of the sheet geometry between the rolls, the numerical simulation is performed until the stationary state is reached with a mesh. In this paper, ALE results are compared to previous Lagrangian simulations and experimental measurement on a U-channel, including springback [less ▲]

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See detailInfluence of thermoelectric coupling on ectopic beats generated by mechano-electric feedback (MEF) in a one-dimensional cardiac fiber model
Collet, Arnaud ULg; Desaive, Thomas ULg; Pierard, Luc ULg et al

in 9th Belgian Day on Biomedical Engineering, Friday November 26th 2010 in the Academy Palace, Hertogstraat 1, 1000 Brussels (2010, November 26)

The influence of thermal processes on electrophysiology has clearly been underlined by Bini et al., using a FitzHugh--Nagumo-type (FHN-type) model. When the temperature is raised, the action potential ... [more ▼]

The influence of thermal processes on electrophysiology has clearly been underlined by Bini et al., using a FitzHugh--Nagumo-type (FHN-type) model. When the temperature is raised, the action potential duration (APD) has been shown to shorten, while the action potential (AP) amplitude decreases, and the conduction velocity increases. In this research, we investigate the effects of thermoelectric coupling on mechano-electric feedback (MEF), and more specifically, on ectopic beats generated by MEF. To investigate these effects, thermoelectric coupling is introduced in a one-dimensional electromechanical model of a cardiac fiber, which considers excitation-contraction coupling (ECC), as well as MEF. [less ▲]

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See detailInfluence of thermoelectric coupling on ectopic beats generated by mechano-electric feedback (MEF) in a one-dimensional cardiac fiber model
Collet, Arnaud ULg; Desaive, Thomas ULg; Pierard, Luc ULg et al

Poster (2010, November 26)

The influence of thermal processes on electrophysiology has clearly been underlined by Bini et al., using a FitzHugh--Nagumo-type (FHN-type) model. When the temperature is raised, the action potential ... [more ▼]

The influence of thermal processes on electrophysiology has clearly been underlined by Bini et al., using a FitzHugh--Nagumo-type (FHN-type) model. When the temperature is raised, the action potential duration (APD) has been shown to shorten, while the action potential (AP) amplitude decreases, and the conduction velocity increases. In this research, we investigate the effects of thermoelectric coupling on mechano-electric feedback (MEF), and more specifically, on ectopic beats generated by MEF. To investigate these effects, thermoelectric coupling is introduced in a one-dimensional electromechanical model of a cardiac fiber, which considers excitation-contraction coupling (ECC), as well as MEF. [less ▲]

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See detailMultiple material mesh generation for biomedical applications
D'Otreppe, Vinciane ULg; Boman, Romain ULg; Ponthot, Jean-Philippe ULg

in Proceedings of the 9th belgian day on biomedical engineering (2010, November 26)

The finite element method is commonly used in biomedical applications for the simulation of the behaviour of biological structures. However, extracting finite element meshes from medical images is still ... [more ▼]

The finite element method is commonly used in biomedical applications for the simulation of the behaviour of biological structures. However, extracting finite element meshes from medical images is still very challenging. We propose an innovative system to create accurate multiple domain tetrahedral meshes from medical images. Our approach is based on an enhanced Marching Tetrahedra algorithm that extracts the boundary surfaces delimiting the different material domains in an integrated manner. Moreover, a surface reconstruction method is employed to ensure that the resulting mesh is a smooth and accurate surface representation of the original sampled structure. Mesh smoothing and decimation algorithms are also revised to conform to the multiple material nature of the system as well as to adhere to the underlying volume data. [less ▲]

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See detailMultiple Material Mesh Generation For Biomedical Applications
D'Otreppe, Vinciane ULg; Boman, Romain ULg; Ponthot, Jean-Philippe ULg

Poster (2010, November 26)

The finite element (FE) method is commonly used in biomedical applications for the simulation of the behaviour of biological structures. A key component in FE simulation is the creation of a finite ... [more ▼]

The finite element (FE) method is commonly used in biomedical applications for the simulation of the behaviour of biological structures. A key component in FE simulation is the creation of a finite element mesh. In medical applications, the meshes should be directly generated from the medical scans. Moreover, biological structures are usually composed of several inner regions that need to be separately segmented, labelled and meshed to be able to apply different material properties in the finite element model. A procedure to create surface meshes from a multi-valued volume data sets is proposed. Following properties are guaranteed: (1) The generated mesh consists of a set of non manifold triangle meshes that separate each connected component in the labelled data set. These interface meshes join each other consistently along their boundaries, i.e., no T junctions nor gaps may appear. (2) The surface mesh is a geometrically accurate representation of the data represented in the medical scans. However, it is not be tainted by the typical aliasing and staircase artifacts that are due to the discrete nature of the voxels. [less ▲]

Detailed reference viewed: 48 (19 ULg)