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See detailNumerical simulation of NO formation in cement rotary kiln
Wang, Shijie; Lu, Jidong; Li, Weijie et al

in Journal of Chemical Industry and Engineering(China) (2006), 57(11), 2631-2637

Detailed reference viewed: 19 (1 ULg)
See detailNumerical simulation of non lethal projectiles on human thorax
Nsiampa Ndompetelo, ULg; Robbe, Cyril ULg; Papy, Alexandre

in Ballistics 2011: 26th International Symposium (2011, September 11)

These last decades have seen the development of a new type of weapons, the non lethal weapons. Unlike the conventional weapons which may cause severe or fatal injuries and whose injury mechanisms are well ... [more ▼]

These last decades have seen the development of a new type of weapons, the non lethal weapons. Unlike the conventional weapons which may cause severe or fatal injuries and whose injury mechanisms are well documented, the non lethal weapons are designed for temporary incapacitation with reversible consequences or minor damage to the human body. They try therefore to fill the gap wherever the use of excessive forces or conventional weapons is not necessary. There are various non lethal technologies but here we will focus on non lethal kinetic energy weapons (NLKEW). The non penetrating characteristics of non lethal projectiles lead to different injury mechanisms to those related to conventional lethal projectiles. In order to better understand these effects and assess the injury severity, experiments are carried out on Post Mortem Human Surrogates (PMHS), animals and mechanical anthropomorphic systems. Nevertheless nowadays with the development of high performance computing systems, numerical simulations based on finite element method are increasingly used because of their cost-effectiveness, their predictive capabilities and their adaptability (for example the possibility of adapting the geometry to take into account various morphologies, …). Physical injury is a consequence of the interaction between the human body and the projectile. To assess the severity of injury, injury criteria are defined. The most used criterion on the assessment of the thorax injury is the maximum viscous criterion. Because of the human body complexity, reliable information on injury mechanisms and tolerance level to the impact of non lethal projectiles is limited. The major challenge in the numerical simulations is the human tissue material model as human tissue responses to impacts are various and complex. As a consequence, models which are biofidelic to the human living tissues are a key issue. To investigate and predict the human thorax response to the impact of the usual non lethal kinetic projectiles (like the FN303, the 40mm COUGAR), a finite element thorax model has been developed from thorax CT-scan images and the projectile FN303 was used. The model was validated by using results (force-time and deflection-time characteristics of the thorax) from experiments on PHMS published in the litterature. Two types of projectiles made of polyvinyl chloride cylinder with 37 mm diameter and respectively 28.5 mm and 100 mm long were used and the human tissue material models were found in open litterature. [less ▲]

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See detailNumerical simulation of nonlinear mechanical problems using Metafor
Boman, Romain ULg

Scientific conference (2014, May 16)

Detailed reference viewed: 40 (7 ULg)
See detailNumerical simulation of P-OLEDs
Nguyen, Ngoc Duy ULg

Report (2012)

Detailed reference viewed: 25 (0 ULg)
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See detailNumerical simulation of peri-implant tissue differentiation in a bone chamber
Geris, Liesbet ULg; Van Oosterwyck, Hans; Andreykiv, A. et al

in European Cells and Materials (2003), 5(2), 16-17

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See detailNumerical simulation of semi-solid thixoforming
Koeune, Roxane ULg; Ponthot, Jean-Philippe ULg

in Int. Conf. on Computational Plasticity, COMPLAS IX (2007)

Detailed reference viewed: 12 (2 ULg)
See detailNumerical simulation of shock-absorber devices for crashworthiness : explicit vs implicit formulation
Ponthot, Jean-Philippe ULg; Graillet, D.

in 32nd ISATA, International Symposium on Automotive Technology and Automation, special session on Automotive Crashworthiness, paper 99 SF004 (1999, June)

Detailed reference viewed: 29 (1 ULg)
Peer Reviewed
See detailNumerical Simulation of Springback in Sheet Metal Forming
Ponthot, Jean-Philippe ULg; Papeleux, Luc ULg; GOHY, S. et al

in Proceedings of ECCOMAS 2000/COMPLAS VI, European Congress on Computational Methods in Applied Sciences and Engineering (2000)

Detailed reference viewed: 17 (1 ULg)
See detailNumerical Simulation of Springback in Sheet Metal Forming Using Linear Shell Elements
Papeleux, Luc ULg; Ponthot, Jean-Philippe ULg; GOHY, S. et al

in Proceedings of IASS-IACM 2000, Fourth International Colloquium on Computation of Shell and Spatial Structure (2000)

Detailed reference viewed: 9 (1 ULg)
See detailNumerical Simulation of Springback in Sheet Metal Forming Using Shell Elements
Papeleux, Luc ULg; GOHY, S.; COLLARD, X. et al

in Proceedings of the Fifth National Belgian Congress on Theoretical and Applied Mechanics (2000)

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See detailNumerical simulation of springback using enhanced assumed strain elements
Bui, Q. V.; Papeleux, Luc ULg; Ponthot, Jean-Philippe ULg

in Journal of Materials Processing Technology (2004), 153(1), 314-318

The quality of springback prediction for a sheet metal forming process depends on a precise estimate of the elasto-plastic stress distribution throughout the metal sheet. The use of low-order conventional ... [more ▼]

The quality of springback prediction for a sheet metal forming process depends on a precise estimate of the elasto-plastic stress distribution throughout the metal sheet. The use of low-order conventional finite elements may be, without any proper treatment, responsible for low quality prediction because of volumetric and shear lockings. In this study, the enhanced assumed strain technique will be exploited for locking removal. The quality of the numerical simulation is evaluated through a comparison with other popular techniques like selective and uniform reduced integration. In contrast to the latter, and thanks to a full numerical integration scheme, the enhanced assumed strain element is very efficient in accurately capturing the development of plastic flow. This enables a reliable prediction of springback even with a rather coarse mesh. (C) 2004 Elsevier B.V. All rights reserved. [less ▲]

Detailed reference viewed: 33 (2 ULg)
See detailNumerical simulation of Springback using enhanced assumed strain elements
BUI, Q. V.; Papeleux, Luc ULg; Ponthot, Jean-Philippe ULg

in Proceedings of AMPT 2003, Advances in Materials and Processing Technologies (2003)

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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 detailNumerical simulation of T-bend of multilayer coated metal sheet using solid-shell element
Ben Bettaieb, Amine ULg; Tuninetti Vásquez, Victor ULg; Duchene, Laurent ULg

in Steel Research International (2012)

The main aim of this paper is to model the T-bend test performed on multilayer coated metal sheets in order to measure the coating flexibility. Because of important uses of polymer coatings in many ... [more ▼]

The main aim of this paper is to model the T-bend test performed on multilayer coated metal sheets in order to measure the coating flexibility. Because of important uses of polymer coatings in many industrial applications and higher requirement on the quality of products, an accurate modeling of the T-bend process is therefore essential. During the modeling with the finite element method, the large thickness ratio between the different layers is likely to produce elements with an unfavorable aspect ratio. Therefore, to avoid obtaining inaccurate results linked to the shape of the elements, solid-shell elements are used in this study. These elements are based on the Enhanced Assumed Strain (EAS) technique and the Assumed Natural Strain (ANS) technique. These techniques permit to avoid locking problems even in very bad conditions (nearly incompressible materials, very thin elements conducting to large aspect ratios, distorted element geometry…). The EAS technique artificially introduces additional degrees of freedom (DOFs) to the element. They permit to increase the flexibility of the element which is very efficient for several locking issues. On the other hand, the ANS technique modifies the interpolation scheme for particular strain components. The ANS technique proved to eliminate the transverse shear locking from the element in bending dominated situations. Besides, a numerical integration scheme dedicated to Solid-Shell elements was implemented. It uses a user-defined number of integration points along the thickness direction, which permits to increase the element accuracy with a mesh containing a reduced number of elements along the thickness direction. The results obtained from numerical simulations are compared with some analytical results in order to check the strain predicted in the coated layer by FEM. This information helps to investigate the coating layer ductility in the real process. [less ▲]

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See detailNumerical simulation of the electrical characteristics of CIGS/CdS/ZnO solar cell heterostructures
Amand, Julien ULg; Nguyen, Ngoc Duy ULg

Poster (2013, September 17)

The electrical characteristics of CIGS-based solar cell heterostructure have been simulated by numerically solving the basic semiconductor equations by means of a finite differences method based on a ... [more ▼]

The electrical characteristics of CIGS-based solar cell heterostructure have been simulated by numerically solving the basic semiconductor equations by means of a finite differences method based on a Scharfetter-Gummel discretization scheme. The electric potential, electric field, carrier concentrations, current densities and recombination rates are obtained as function of the space coordinate and the bias voltage. Starting with the analysis of a single absorber layer structure sandwiched between two metal electrodes, we subsequently studied the properties of the CIGS/ZnO pn heterojunction and the influence of the buffer layer thickness in the CIGS/CdS/ZnO on the cell electrical response. A special focus was also given to the influence of grain boundaries in the bulk of CIGS depending on the defects nature and concentration. [less ▲]

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See detailNumerical simulation of the electrical characteristics of CIGS/CdS/ZnO solar cell heterostructures
Amand, Julien ULg; Nguyen, Ngoc Duy ULg

Poster (2013, December 03)

The electrical characteristics of CIGS-based solar cell heterostructure have been simulated by numerically solving the basic semiconductor equations by means of a finite differences method based on a ... [more ▼]

The electrical characteristics of CIGS-based solar cell heterostructure have been simulated by numerically solving the basic semiconductor equations by means of a finite differences method based on a Scharfetter-Gummel discretization scheme. The electric potential, electric field, carrier concentrations, current densities and recombination rates are obtained as function of the space coordinate and the bias voltage. Starting with the analysis of a single absorber layer structure sandwiched between two metal electrodes, we subsequently studied the properties of the CIGS/ZnO pn heterojunction and the influence of the buffer layer thickness in the CIGS/CdS/ZnO on the cell electrical response. A special focus was also given to the influence of grain boundaries in the bulk of CIGS depending on the defects nature and concentration. Electrical measurements including admittance spectroscopy were performed on samples for comparison to be further lead. Motivations This research is part of the project IQuaReS (Innovative in-line Quality control for Renewable Solar solutions) that aims to develop an in-line quality control tool for manufactured CIGS-based solar cells, based on electrical and optoelectrical, preferably non-invasive measurement methods. Exploratory simulations aim to isolate signature patterns that could be sought in experimental measurements . [less ▲]

Detailed reference viewed: 30 (7 ULg)
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See detailNumerical simulation of the fluid-structure interaction between air blast waves and free-standing plates
Kambouchev, Nayden; Noels, Ludovic ULg; Radovitzky, Raúl

in Computers & Structures (2007), 85(nov-14 Sp. Iss. SI), 923931

A numerical method is used to compute the flow field corresponding to blast waves of different incident profiles propagating in air and impinging on free-standing plates. The method is suitable for the ... [more ▼]

A numerical method is used to compute the flow field corresponding to blast waves of different incident profiles propagating in air and impinging on free-standing plates. The method is suitable for the consideration of compressibility effects in the fluid and their influence on the plate dynamics. The history of the pressure experienced by the plate is extracted from numerical simulations for arbitrary blast strengths and plate masses and used to infer the impulse per unit area transmitted to the plate. The numerical results complement some recent analytical solutions in the intermediate range of plate masses and arbitrary blast intensities where exact solutions are not available. The resulting beneficial effect of the fluid-structure interaction (FSI) in reducing transmitted impulse in the presence of compressibility effects is discussed. In particular, it is shown that in order to take advantage of the impulse reduction provided by the FSI effect, large plate displacements are required which, in effect, may limit the practical applicability of exploiting FSI effects in the design of blast-mitigating systems. (C) 2006 Elsevier Ltd. All rights reserved. [less ▲]

Detailed reference viewed: 93 (6 ULg)
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See detailNumerical simulation of the magnetization of high-temperature superconductors: a 3D finite element method using a single time-step iteration
Lousberg, Grégory ULg; Ausloos, Marcel ULg; Geuzaine, Christophe ULg et al

in Superconductor Science and Technology (2009), 22

In this paper, we report progress towards a 3D finite element model for the magnetization of a high-temperature superconductor (HTS): we suggest a method that takes into account a power law conductivity ... [more ▼]

In this paper, we report progress towards a 3D finite element model for the magnetization of a high-temperature superconductor (HTS): we suggest a method that takes into account a power law conductivity and demagnetization effects, while neglecting the effects associated with currents that are not perpendicular to the local magnetic induction. We consider samples that are subjected to a uniform magnetic field varying linearly with time. Their magnetization is calculated by means of a weak formulation in the magnetostatic approximation of the Maxwell equations (A–φ formulation). An implicit method is used for the temporal resolution (backward Euler scheme) and is solved with the open source solver GetDP. Fixed point iterations are used to deal with the power law conductivity of HTS. The finite element formulation is validated for an HTS tube with large n value by comparing with results obtained with other well-established methods. We show that carrying out the calculations with a single time-step (as opposed to many small time-steps) produces results with excellent accuracy in a drastically reduced simulation time. The numerical method is extended to the study of the trapped magnetization of cylinders that are drilled with different arrays of columnar holes arranged parallel to the cylinder axis. [less ▲]

Detailed reference viewed: 145 (54 ULg)