References of "Ponthot, Jean-Philippe"
     in
Bookmark and Share    
Full Text
See detailA new formulation of internal forces for non-linear hypoelastic constitutive models verifying conservation laws
Noels, Ludovic ULg; Stainier, Laurent ULg; Ponthot, Jean-Philippe ULg et al

in Bathe, K. J. (Ed.) Second MIT Conference on Fluid and Solid Mechanics (2003)

This paper proposes a new formulation of the internal forces for hypoelastic constitutive models ensuring that the elastic work of deformation can be restored by the scheme. Moreover, we demonstrate that ... [more ▼]

This paper proposes a new formulation of the internal forces for hypoelastic constitutive models ensuring that the elastic work of deformation can be restored by the scheme. Moreover, we demonstrate that the work of the plastic deformation is positive and consistent with the material model. [less ▲]

Detailed reference viewed: 20 (4 ULg)
See detailOptimization methods for parameter identification of constitutive models in finite viscoplasticity and damage
Stainier, Laurent ULg; KLEINERMANN, J.-P.; Ponthot, Jean-Philippe ULg

in Proceedings of PLASTICITY 2003 (2003)

Detailed reference viewed: 5 (1 ULg)
See detailCaracterization del comportamiento mecanico de aceros para embuticion profunda
GARCIA, C.; CELENTANO, D.; Ponthot, Jean-Philippe ULg

in Proceedings of the joint conference Jornadas SAM, el Congreso Nacional de Metalurgia y Materiales de Chile (2003)

Detailed reference viewed: 52 (1 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)

Detailed reference viewed: 9 (2 ULg)
See detailEfficient algorithmic approach for mixed lubrication in cold rolling
STEPHANY, A.; Ponthot, Jean-Philippe ULg; COLLETTE, C. et al

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

Detailed reference viewed: 5 (1 ULg)
Peer Reviewed
See detailNouveau concept algorithmique pour un modèle de laminage à froid en régime mixte
STEPHANY, A.; Ponthot, Jean-Philippe ULg; COLLETTE, C. et al

in Proceedings of the 6ème colloque national en calcul des structures (2003)

Detailed reference viewed: 13 (1 ULg)
Peer Reviewed
See detailNew algorithm concept for a model of mixed lubrication in cold rolling
STEPHANY, A.; Ponthot, Jean-Philippe ULg; COLLETTE, C. et al

in Proceedings of METEC 2003, European Rolling Conference (2003)

Detailed reference viewed: 15 (1 ULg)
Full Text
Peer Reviewed
See detailUn nouveau schéma d'intégration conservatif pour des modèles constitutifs hypoélastiques irréversibles.
Noels, Ludovic ULg; Stainier, Laurent ULg; Ponthot, Jean-Philippe ULg

in Potier-Ferry, M.; Bonnet, M.; Bignonnet, A. (Eds.) Actes du Sixième Colloque National en Calcul des Structures (2003)

Ce travail propose une nouvelle évaluation des forces internes pour les modèles constitutifs hypoélastiques irréversibles dans le cadre de la méthode des éléments-finis en grandes transformations. Nous ... [more ▼]

Ce travail propose une nouvelle évaluation des forces internes pour les modèles constitutifs hypoélastiques irréversibles dans le cadre de la méthode des éléments-finis en grandes transformations. Nous démontrons que cette expression des forces internes utilisée avec un schéma d'intégration du point milieu conduit à un algorithme d'intégration consistant avec les lois de la thermodynamique. [less ▲]

Detailed reference viewed: 45 (1 ULg)
Full Text
Peer Reviewed
See detailNumerical simulation of viscoplastic and frictional heating during finite deformation of metal. Part I: Theory
Adam, Laurent; Ponthot, Jean-Philippe ULg

in Journal of Engineering Mechanics (2002), 128(11), 1215-1221

In this paper we will apply the theoretical framework developed in Part I to various metal forming processes. These numerical simulations are exposed showing the capability of the formulation to simulate ... [more ▼]

In this paper we will apply the theoretical framework developed in Part I to various metal forming processes. These numerical simulations are exposed showing the capability of the formulation to simulate finite anisothermal deformation of solids and thermal field evolution due to viscoplastic and frictional heating. [less ▲]

Detailed reference viewed: 9 (2 ULg)
Full Text
Peer Reviewed
See detailNumerical Simulation of Viscoplastic and Frictional Heating during Finite Deformation of Metal. Part II: Applications
Adam, Laurent; Ponthot, Jean-Philippe ULg

in Journal of Engineering Mechanics (2002), Vol. 128

In this paper we will apply the theoretical framework developed in Part I to various metal forming processes. These numerical simulations are exposed showing the capability of the formulation to simulate ... [more ▼]

In this paper we will apply the theoretical framework developed in Part I to various metal forming processes. These numerical simulations are exposed showing the capability of the formulation to simulate finite anisothermal deformation of solids and thermal field evolution due to viscoplastic and frictional heating. [less ▲]

Detailed reference viewed: 13 (0 ULg)
See detailSimulation of Springback with Enhanced Assumed Strain Elements
BUI, Q. V.; NGUYEN, H. G.; Papeleux, Luc ULg et al

in Proceedings of NUMISHEET 2002 (2002, October)

Detailed reference viewed: 17 (2 ULg)
Full Text
Peer Reviewed
See detailFinite element simulation of springback in sheet metal forming
Papeleux, Luc ULg; Ponthot, Jean-Philippe ULg

in Journal of Materials Processing Technology (2002), 125(Sp. Iss. SI), 785-791

Although finite element analysis (FEA) is successful in simulating complex industrial sheet forming operations, the accurate and reliable application of this technique to springback has not been widely ... [more ▼]

Although finite element analysis (FEA) is successful in simulating complex industrial sheet forming operations, the accurate and reliable application of this technique to springback has not been widely demonstrated. Several physical parameters, as well as numerical, influence this phenomenon and its numerical prediction. In this paper, we investigate the impact of these parameters on the springback appearing in a 2D U-draw bending. (C) 2002 Elsevier Science B.V. All rights reserved. [less ▲]

Detailed reference viewed: 43 (5 ULg)
Full Text
Peer Reviewed
See detailNumerical Simulation of Lubricated Contact in Rolling Processes
Boman, Romain ULg; Ponthot, Jean-Philippe ULg

in Journal of Materials Processing Technology (2002), 125-126

In this paper, the lubrication problem in numerical simulation of rolling process is presented. In this case, the recent and complex model of Marsault for the solution of the mixed lubrication regime has ... [more ▼]

In this paper, the lubrication problem in numerical simulation of rolling process is presented. In this case, the recent and complex model of Marsault for the solution of the mixed lubrication regime has been implemented and tested. This model requires the use of the finite difference method to work properly. We will discuss the advantages and the difficulties encountered when trying to solve the same problem with the finite element method in a general frame. Finally, a finite element formulation for the solution of the time-dependent Reynolds' equation coupled with the deformation of the workpiece is proposed. (C) 2002 Elsevier Science B.V. All rights reserved. [less ▲]

Detailed reference viewed: 106 (10 ULg)
See detailSpringback Prediction in Sheet Metal Forming
Papeleux, Luc ULg; Ponthot, Jean-Philippe ULg

in Proceedings of ACOMEN 2002 (2002, May)

Detailed reference viewed: 5 (1 ULg)
Full Text
Peer Reviewed
See detailEstimation of rubber sliding friction from asperity interaction modeling
Bui, Q. V.; Ponthot, Jean-Philippe ULg

in Wear (2002), 252(1-2), 150-160

Interaction between a soft rubber asperity and its hard counterpart is traced with the help of a finite element computation. The analysis is aimed to estimate the influence of adhesion between rubber and ... [more ▼]

Interaction between a soft rubber asperity and its hard counterpart is traced with the help of a finite element computation. The analysis is aimed to estimate the influence of adhesion between rubber and rigid surfaces and the energy losses arising from the deformation of rubber bulk to the sliding resistance. At the contact zone, interfacial bonds are formed due to adhesion and their resistance to sliding is represented by the shear strength of the contact interface. In the rubber bulk, the hysteresis loss is calculated using an appropriate model of the viscoelastic mechanical behavior of rubber for large strains. Dependence of friction on sliding speeds and temperature is hence detected. Influence of surface roughness and contact pressure on friction is also examined. (C) 2002 Elsevier Science B.V. All rights reserved. [less ▲]

Detailed reference viewed: 43 (0 ULg)
Full Text
Peer Reviewed
See detailDétermination automatique de la taille du pas de temps pour les schémas implicites en dynamique non-linéaire
Noels, Ludovic ULg; Stainier, Laurent ULg; Ponthot, Jean-Philippe ULg et al

in Mécanique & Industries (2002), 3(1), 63-77

Pour les problèmes caractérisés par de fortes non-linéarités, ainsi que des phénomènes d'impacts et de contacts, une stratégie d'intégration à pas de temps variables est particulièrement intéressante. Ces ... [more ▼]

Pour les problèmes caractérisés par de fortes non-linéarités, ainsi que des phénomènes d'impacts et de contacts, une stratégie d'intégration à pas de temps variables est particulièrement intéressante. Ces phénomènes sont par exemple rencontrés lors de l'étude dynamique d'une interaction aube-carter d'un moteur d'avion, le cas le plus critique étant la perte de l'aube. Une stratégie d'intégration implicite à pas de temps constant donne rarement satisfaction du fait qu'il est pratiquement impossible de déterminer une durée de pas qui ne conduise pas à la divergence ou à un coût de calcul prohibitif. Une gestion automatique du pas de temps, qui tient compte de l'histoire récente des accélérations dans le corps considéré, est proposée. En fait, l'algorithme est basé sur la mesure de l'erreur d'intégration des équations d'équilibre. Cela permet d'intégrer correctement les phénomènes transitoires avec un pas de temps très long (en régime) ou très petit (lors de la perte d'aube), en garantissant une bonne précision en un temps de calcul raisonnable. De plus, un algorithme qui décide automatiquement de recalculer ou non, la matrice hessienne est proposé. Cet algorithme permet d'éviter un nombre important de remises à jour de cette matrice, ce qui permet de réduire le coût de calcul tout en assurant la convergence. Enfin, un critère de divergence des itérations est proposé. Afin d'illustrer l'efficacité des algorithmes développés, des simulations numériques sont présentées. Il s'agit aussi bien de problèmes académiques que de problèmes industriels (contacts aubes carter). [less ▲]

Detailed reference viewed: 167 (4 ULg)
Full Text
Peer Reviewed
See detailCombined implicit-explicit algorithms for non-linear structural dynamics
Noels, Ludovic ULg; Stainier, Laurent ULg; Ponthot, Jean-Philippe ULg et al

in Revue Européenne des Éléments Finis (2002), 11(5), 565-591

To solve fast dynamic problems, an explicit method is the most adapted. But for slower dynamics, an implicit method is more stable. The industrial problems are governed by high frequency (impact ... [more ▼]

To solve fast dynamic problems, an explicit method is the most adapted. But for slower dynamics, an implicit method is more stable. The industrial problems are governed by high frequency (impact, ...) during short time intervals and slower dynamics (spring-back, ...) during other time intervals. The optimal solution is then to have both implicit algorithm and explicit methods readily available in the same code and to be able to switch automatically from one to another. Criteria that decide when to shift from a method to another have been developed here. Implicit balanced restarting conditions that annihilate numerical oscillations resulting for an explicit calculation are also proposed. [less ▲]

Detailed reference viewed: 68 (8 ULg)
Full Text
Peer Reviewed
See detailSelf-adapting time integration management in crash-worthiness and sheet metal forming computations
Noels, Ludovic ULg; Stainier, Laurent ULg; Ponthot, Jean-Philippe ULg

in International Journal of Vehicle Design (2002), 30(1-2), 67-114

Variable step strategies are especially well suited to deal with problems characterized by high non-linearity and contact/impact, and resolved with an implicit scheme. Both phenomena are typical of ... [more ▼]

Variable step strategies are especially well suited to deal with problems characterized by high non-linearity and contact/impact, and resolved with an implicit scheme. Both phenomena are typical of dynamic simulations of contact-impact problems, as well as sheet metal forming. Constant step size strategies do not give a satisfactory answer for this kind of problem, since it is very difficult, if not impossible, for the user to find an appropriate time step that does not lead to divergence nor generate extremely costly computations. An automatic time stepping algorithm is proposed, which takes into account the recent history of accelerations in the deformable bodies under consideration. More precisely, the adaptation algorithm is based on estimators of the integration error of the differential dynamic balance equations. This allows for adaptation of the step size to capture correctly the transient phenomena, with characteristic times which can range from relatively long (after contact, or during sheet metal forming) to very short (during contact-impact). thus ensuring precision while keeping the computation cost to a minimum. Furthermore, we will see that this strategy can be used in explicit schemes. Additionally, the proposed algorithm automatically takes decisions regarding the necessity of updating the tangent matrix or stopping the iterations, further reducing the computational costs especially, when the Augmented Lagrangian method is used. As an illustration of the capabilities of this algorithm, several numerical simulations (shock absorber devices for vehicle crash-worthiness or sheet metal forming) problems will be presented. Other simulations pertaining to the sheet metal forming for vehicle structures will also be investigated, thus demonstrating the versatility, the capabilities and the efficiency of the proposed strategy. [less ▲]

Detailed reference viewed: 49 (0 ULg)