This work is devoted to the analysis, by numerical simulation, of the elastoplastic behavior of m... more This work is devoted to the analysis, by numerical simulation, of the elastoplastic behavior of materi als and the unilateral contact with Coulomb’s dry friction. Wit h this objective, we present a solution algorithm f or elastoplastic evolution, taking into account the un ilateral contact with Coulomb’s dry friction. This algorithm consists in an incremental formulation from tempora l elastoplastic and unilateral contact laws. The la tter and the non standard behavior of material are described by means of the bipotential theory. This allows us to use a variational formulation based on a minimum principle. To avoid the non differentiability of the bipote ntial, the penalization and the Uzawa’s algorithm are used. Mots cles : bipotentiel, plastcite, contact
Bulletin of Chemical Reaction Engineering & Catalysis, 2022
Today, hydrogen has become one of the most promising clean energy. Several processes allow obtain... more Today, hydrogen has become one of the most promising clean energy. Several processes allow obtaining hydrogen, among them there is the Water Gas Shift (WGS) reaction. On an industrial scale, WGS reaction takes place at high pressure [25–35 bar]. At high pressure, the cost of the process rises due to the energy consumed by compression, and the reduction in the lifetime of the equipment and the catalyst. At low pressures, catalyst lifetime can reach many years and the energy cost is reduced. It is for this reason that we are interested in modelling and simulation of a WGS converter operating at low pressures close to atmospheric pressure. In this work, a numerical study was conducted in order to determine the conditions allowing good rector operating at low pressure. A number of drawbacks of the process were identified. These drawbacks are essentially the non-negligible pressure drops and the strong intraparticle diffusion resistances. The prediction of the concentrations and the reac...
Bulletin of Chemical Reaction Engineering & Catalysis, 2022
Today, hydrogen has become one of the most promising clean energy. Several processes allow obtain... more Today, hydrogen has become one of the most promising clean energy. Several processes allow obtaining hydrogen, among them there is the Water Gas Shift (WGS) reaction. On an industrial scale, WGS reaction takes place at high pressure [25–35 bar]. At high pressure, the cost of the process rises due to the energy consumed by compression, and the reduction in the lifetime of the equipment and the catalyst. At low pressures, catalyst lifetime can reach many years and the energy cost is reduced. It is for this reason that we are interested in modelling and simulation of a WGS converter operating at low pressures close to atmospheric pressure. In this work, a numerical study was conducted in order to determine the conditions allowing good rector operating at low pressure. A number of drawbacks of the process were identified. These drawbacks are essentially the non-negligible pressure drops and the strong intraparticle diffusion resistances. The prediction of the concentrations and the reac...
Résumé : Nous proposons dans ce travail un nouvel algorithme d’optimisation des coques minces sph... more Résumé : Nous proposons dans ce travail un nouvel algorithme d’optimisation des coques minces sphériques en utilisant la théorie de l’analyse et les algorithmes génétiques. L’analyse limite permet de calculer la charge limite de la structure à l’amorce de l’écoulement plastique ce qui permet de tirer profit du maximum de résistance de la coque, car la coque est « optimale » lorsqu’elle travaille à la limite de sa résistance avec un minimum de matière pour supporter un chargement donné. Pour calculer la charge limite de la structure on applique les théorèmes généraux de l’analyse limite qui mènent vers une méthode directe combinant la programmation mathématique et la méthode des éléments finis. Pour converger vers la coque optimale, la méthode proposée transforme le problème d’optimisation en la résolution d’une série de problèmes d’analyse limite en faisant appel à un algorithme génétique. Ainsi, cette méthode permet de rapprocher la plasticité, la recherche opérationnelle et la gén...
2016 Global Summit on Computer & Information Technology (GSCIT), 2016
Many undergraduate students often have difficultieswith design algorithms. This problem leads to ... more Many undergraduate students often have difficultieswith design algorithms. This problem leads to a perpetual failurein the appropriation and assimilation of algorithmic foundations. To address this issue, we propose a teaching approach whichaims more specifically at constructing progressively problemsolving skill among novices as well as providing a design method, which can be adopted in other disciplines to conceive coursesbased on problem based learning (PBL), eliciting motivation, giving meaning to the knowledge to be learnt and engaginglearners in the learning process. An experimentation was carriedout to investigate the effectiveness of the designed learningenvironment. The results stated that the majority of students ofPBL group were either satisfied or extremely satisfied withproblem based learning approach and show significantly greatanalysis and design skills than traditional groups.
Assimilating an algorithmic course is a persistent problem for many undergraduate students. The m... more Assimilating an algorithmic course is a persistent problem for many undergraduate students. The major problem faced by students is the lack of problem solving ability and flexibility. Therefore, students are generally passive, unmotivated and unable to mobilize all the acquired knowledge (loops, test, variables, etc.) to deal with new encountered problems. Our study is structured around building, step by step, problem solving skills among novice learners. Our approach is based on the use of problem based learning in an e-Learning environment. We begin by establishing a cognitive model which represents knowledge elements, grouped into categories of skills, judged necessary to be appropriated. We then propose a problem built on a concrete situation which aims to actively construct a skill category. We conclude by presenting around the proposed problem a pedagogical scenario for the set of learning activities designed to be incorporated in an E-learning platform.
Dans cet article, nous avons posé le problème de l'optimisation dimensionnelle des structures... more Dans cet article, nous avons posé le problème de l'optimisation dimensionnelle des structures en général et des coques minces axisymétriques de révolution en particulier. La formulation que nous avons proposée est basée sur l'utilisation de la théorie de l'analyse limite et les algorithmes génétiques (Holland, 1976). Cette approche permet de simplifier le problème de dimensionnement en se débarrassant des variables auxiliaires, introduites généralement par la discrétisation de la structure en éléments finis, pour ne garder que les variables design. Le problème de l'analyse limite est résolu par l'utilisation d'une méthode déterministe de la programmation mathématique (Bideq, 1998). Le problème de dimensionnement optimal est résolu en faisant appel aux algorithmes génétiques.
... plaques en flexion et des coques de révolution par la programmation mathématique linéaire (La... more ... plaques en flexion et des coques de révolution par la programmation mathématique linéaire (Lance 64). L'utilisation de la méthode des éléments finis a permis d'obtenir des résultats plus intéressants (Hodge, 68), (Maier, 68). ...
This work is devoted to the analysis, by numerical simulation, of the elastoplastic behavior of m... more This work is devoted to the analysis, by numerical simulation, of the elastoplastic behavior of materi als and the unilateral contact with Coulomb’s dry friction. Wit h this objective, we present a solution algorithm f or elastoplastic evolution, taking into account the un ilateral contact with Coulomb’s dry friction. This algorithm consists in an incremental formulation from tempora l elastoplastic and unilateral contact laws. The la tter and the non standard behavior of material are described by means of the bipotential theory. This allows us to use a variational formulation based on a minimum principle. To avoid the non differentiability of the bipote ntial, the penalization and the Uzawa’s algorithm are used. Mots cles : bipotentiel, plastcite, contact
Bulletin of Chemical Reaction Engineering & Catalysis, 2022
Today, hydrogen has become one of the most promising clean energy. Several processes allow obtain... more Today, hydrogen has become one of the most promising clean energy. Several processes allow obtaining hydrogen, among them there is the Water Gas Shift (WGS) reaction. On an industrial scale, WGS reaction takes place at high pressure [25–35 bar]. At high pressure, the cost of the process rises due to the energy consumed by compression, and the reduction in the lifetime of the equipment and the catalyst. At low pressures, catalyst lifetime can reach many years and the energy cost is reduced. It is for this reason that we are interested in modelling and simulation of a WGS converter operating at low pressures close to atmospheric pressure. In this work, a numerical study was conducted in order to determine the conditions allowing good rector operating at low pressure. A number of drawbacks of the process were identified. These drawbacks are essentially the non-negligible pressure drops and the strong intraparticle diffusion resistances. The prediction of the concentrations and the reac...
Bulletin of Chemical Reaction Engineering & Catalysis, 2022
Today, hydrogen has become one of the most promising clean energy. Several processes allow obtain... more Today, hydrogen has become one of the most promising clean energy. Several processes allow obtaining hydrogen, among them there is the Water Gas Shift (WGS) reaction. On an industrial scale, WGS reaction takes place at high pressure [25–35 bar]. At high pressure, the cost of the process rises due to the energy consumed by compression, and the reduction in the lifetime of the equipment and the catalyst. At low pressures, catalyst lifetime can reach many years and the energy cost is reduced. It is for this reason that we are interested in modelling and simulation of a WGS converter operating at low pressures close to atmospheric pressure. In this work, a numerical study was conducted in order to determine the conditions allowing good rector operating at low pressure. A number of drawbacks of the process were identified. These drawbacks are essentially the non-negligible pressure drops and the strong intraparticle diffusion resistances. The prediction of the concentrations and the reac...
Résumé : Nous proposons dans ce travail un nouvel algorithme d’optimisation des coques minces sph... more Résumé : Nous proposons dans ce travail un nouvel algorithme d’optimisation des coques minces sphériques en utilisant la théorie de l’analyse et les algorithmes génétiques. L’analyse limite permet de calculer la charge limite de la structure à l’amorce de l’écoulement plastique ce qui permet de tirer profit du maximum de résistance de la coque, car la coque est « optimale » lorsqu’elle travaille à la limite de sa résistance avec un minimum de matière pour supporter un chargement donné. Pour calculer la charge limite de la structure on applique les théorèmes généraux de l’analyse limite qui mènent vers une méthode directe combinant la programmation mathématique et la méthode des éléments finis. Pour converger vers la coque optimale, la méthode proposée transforme le problème d’optimisation en la résolution d’une série de problèmes d’analyse limite en faisant appel à un algorithme génétique. Ainsi, cette méthode permet de rapprocher la plasticité, la recherche opérationnelle et la gén...
2016 Global Summit on Computer & Information Technology (GSCIT), 2016
Many undergraduate students often have difficultieswith design algorithms. This problem leads to ... more Many undergraduate students often have difficultieswith design algorithms. This problem leads to a perpetual failurein the appropriation and assimilation of algorithmic foundations. To address this issue, we propose a teaching approach whichaims more specifically at constructing progressively problemsolving skill among novices as well as providing a design method, which can be adopted in other disciplines to conceive coursesbased on problem based learning (PBL), eliciting motivation, giving meaning to the knowledge to be learnt and engaginglearners in the learning process. An experimentation was carriedout to investigate the effectiveness of the designed learningenvironment. The results stated that the majority of students ofPBL group were either satisfied or extremely satisfied withproblem based learning approach and show significantly greatanalysis and design skills than traditional groups.
Assimilating an algorithmic course is a persistent problem for many undergraduate students. The m... more Assimilating an algorithmic course is a persistent problem for many undergraduate students. The major problem faced by students is the lack of problem solving ability and flexibility. Therefore, students are generally passive, unmotivated and unable to mobilize all the acquired knowledge (loops, test, variables, etc.) to deal with new encountered problems. Our study is structured around building, step by step, problem solving skills among novice learners. Our approach is based on the use of problem based learning in an e-Learning environment. We begin by establishing a cognitive model which represents knowledge elements, grouped into categories of skills, judged necessary to be appropriated. We then propose a problem built on a concrete situation which aims to actively construct a skill category. We conclude by presenting around the proposed problem a pedagogical scenario for the set of learning activities designed to be incorporated in an E-learning platform.
Dans cet article, nous avons posé le problème de l'optimisation dimensionnelle des structures... more Dans cet article, nous avons posé le problème de l'optimisation dimensionnelle des structures en général et des coques minces axisymétriques de révolution en particulier. La formulation que nous avons proposée est basée sur l'utilisation de la théorie de l'analyse limite et les algorithmes génétiques (Holland, 1976). Cette approche permet de simplifier le problème de dimensionnement en se débarrassant des variables auxiliaires, introduites généralement par la discrétisation de la structure en éléments finis, pour ne garder que les variables design. Le problème de l'analyse limite est résolu par l'utilisation d'une méthode déterministe de la programmation mathématique (Bideq, 1998). Le problème de dimensionnement optimal est résolu en faisant appel aux algorithmes génétiques.
... plaques en flexion et des coques de révolution par la programmation mathématique linéaire (La... more ... plaques en flexion et des coques de révolution par la programmation mathématique linéaire (Lance 64). L'utilisation de la méthode des éléments finis a permis d'obtenir des résultats plus intéressants (Hodge, 68), (Maier, 68). ...
Uploads