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Etablissement d'une enveloppe bi-axiale à la rupture des composites stratifiés / Anissa Bouadid in REVUE DES COMPOSITES ET DES MATERIAUX AVANCES, Vol. 21, N° 2 (05-06-07-08/2011)
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Titre : Etablissement d'une enveloppe bi-axiale à la rupture des composites stratifiés Type de document : texte imprimé Auteurs : Anissa Bouadid, Auteur ; Oualid Limam, Auteur Année de publication : 2011 Article en page(s) : p. 209-220 Note générale : Bibliogr. Langues : Français (fre) Catégories : Composites -- Rupture
Stratifiés -- RuptureTags : 'Composites stratifiés' 'Charge bi-axiale' 'Analyse limite' 'Critère rupture' 'Optimisation non linéaire' Index. décimale : 620.11 Matériaux (propriétés, résistance) Résumé : Une approche par l'intérieur est proposée pour les composites stratifiés sous un chargement bi-axial. Pour les composites stratifiés donnés, un champ de contrainte 3D est défini par le pli. L'approche par l'intérieur de l'analyse limite est appliquée et donne une borne inférieure de la charge ultime de rupture du stratifié sous un chargement bi-axial. Un critère quadratique simplifié de type Tsai-Wu modifié est considéré par pli. L'approche par l'intérieur devient un problème de maximisation non linéaire. Une comparaison entre les enveloppes de rupture bi-axiale expérimentales et théoriques est faite. Note de contenu : - Géométrie et modèle mécanique
- Tenseur des contraintes, équations d'équilibre, conditions aux limites
- Critère de rupture dans les couches
- Approche par l'intérieur
- Mise en oeuvre du problème de maximisation de l'enveloppe bi-axiale
- Comparaison avec les résultats expérimentaux de l'essai bi-axialDOI : 10.3166/rcma.21.209-220 Permalink : https://e-campus.itech.fr/pmb/opac_css/index.php?lvl=notice_display&id=11831
in REVUE DES COMPOSITES ET DES MATERIAUX AVANCES > Vol. 21, N° 2 (05-06-07-08/2011) . - p. 209-220[article]Réservation
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Code-barres Cote Support Localisation Section Disponibilité 013228 - Périodique Bibliothèque principale Documentaires Disponible Analysis of the various processes downstream cathodic hydrogen charging, I: Diffusion, laboratory permeation and measurement of hydrogen content and diffusion coefficient / Jean-Louis Crolet in MATERIAUX & TECHNIQUES, Vol. 104, N° 2 (2016)
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Titre : Analysis of the various processes downstream cathodic hydrogen charging, I: Diffusion, laboratory permeation and measurement of hydrogen content and diffusion coefficient Type de document : texte imprimé Auteurs : Jean-Louis Crolet, Auteur Année de publication : 2016 Article en page(s) : 17 p. Note générale : Bibliogr. Langues : Anglais (eng) Tags : 'Charge d'hydrogène cathodique' 'Coefficient de diffusion' transitoire' 'Laboratoire perméation' 'Teneur en hydrogène' Index. décimale : 620.11 Matériaux (propriétés, résistance) Résumé : The new views of 2000 on cathodic hydrogen charging are introduced in the numerical modelling of the downstream hydrogen diffusion, and this Part I deals with artificial laboratory permeation with electrochemical measurements on a Pd coated exit face. The “true” transients and steady state are thus calculated for the concentration profiles c(x,t) and the permeation flux Jperm, as well as the permeation efficiency Ep. The former nomenclature in term of thin vs thick membranes is indeed altered by high vs low charging fluxes, or high, medium and low, or still better, very high and moderately high, and very low and moderately low. Results are then compared to the historical calculation tools based on the boundary condition of a constant surface concentration c0 at the entry face. These mathematical tools had been developed a long time ago for permeation under gaseous charging, and they are still valid in this case, but since the abandonment of the Bockris mechanism of discharge-recombination, they are basically invalid for the new cathodic charging by direct proton transfer. More generally, it is emphasised how the two charging modes are different for any subsequent transport process, and more will be addressed in Part II. Then, the totally unexpected consequences on the mechanism of sulfide stress cracking (SSC) will be addressed in Parts III and IV. Note de contenu : - INTRODUCTION : The role of time and fortuity - The "old" hydrogen - The "new" hydrogen
- NUMERICAL MODELLING : Diffusion basics - Artificial laboratory permeation - Joined measurement of the hydrogen content co and diffusion coefficient DHRéférence de l'article : 205 DOI : http://dx.doi.org/10.1051/mattech/2016007 En ligne : http://www.mattech-journal.org/articles/mattech/pdf/2016/02/mt150085.pdf Format de la ressource électronique : Permalink : https://e-campus.itech.fr/pmb/opac_css/index.php?lvl=notice_display&id=26656
in MATERIAUX & TECHNIQUES > Vol. 104, N° 2 (2016) . - 17 p.[article]Réservation
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Code-barres Cote Support Localisation Section Disponibilité 18180 - Périodique Bibliothèque principale Documentaires Disponible Analysis of the various processes downstream cathodic hydrogen charging, II : Charging transients, precharging and natural permeation / Jean-Louis Crolet in MATERIAUX & TECHNIQUES, Vol. 104, N° 2 (2016)
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Titre : Analysis of the various processes downstream cathodic hydrogen charging, II : Charging transients, precharging and natural permeation Type de document : texte imprimé Auteurs : Jean-Louis Crolet, Auteur Année de publication : 2016 Article en page(s) : 16 p. Note générale : Appendices - Bibliogr. Langues : Anglais (eng) Tags : 'Charge d'hydrogène cathodique' 'Transport de Diffusion' transitoire' 'Mesure Airstream' 'Test HIC' Index. décimale : 620.11 Matériaux (propriétés, résistance) Résumé : The new views of the subject since 2000 on cathodic hydrogen charging are introduced through the numerical modelling of the downstream hydrogen diffusion, and this Part II deals with other experimental issues not covered in the laboratory permeation described in Part I: these include HIC testing of plane sheet in two-face exposure, SSC testing and cylindrical tensile specimen, necessarily imperfect quenching of precharged specimens, impossible confusion between trapping and poor degassing, and natural permeation in the field. Orders of magnitude are given for the practical application of present calculations, and the role of alloying is also mentioned, as well as that of corrosion layers. An example of what should no longer be done is also discussed, namely the re-use of all the historical calculation tools available in the literature, since they are strictly incompatible with the present views on cathodic charging. Actually, such “approximation” would range from good or fair to awfully poor, but this depends on each calculation type. The method of airstream measurement is also discussed in the light of this new modelling, as well as the basic principles of fitness-for-purpose and application specific testing for full HIC-resistance. Note de contenu : - NUMERICAL MODELLING : Plane sheet in two face exposure - Cylindrical tensile specimen - Quenching of precharged specimens - Poor degassing vs. trapping - Natural permeation in the field - Influence of corrosion layers
- CONSEQUENCES : Orders of magnitude - Role of alloying - Practical application - Airstream measurement devices - Fitness-for-purpose and application specific testingRéférence de l'article : 206 DOI : http://dx.doi.org/10.1051/mattech/2016013 En ligne : http://www.mattech-journal.org/articles/mattech/pdf/2016/02/mt150086.pdf Format de la ressource électronique : Permalink : https://e-campus.itech.fr/pmb/opac_css/index.php?lvl=notice_display&id=26657
in MATERIAUX & TECHNIQUES > Vol. 104, N° 2 (2016) . - 16 p.[article]Réservation
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Code-barres Cote Support Localisation Section Disponibilité 18180 - Périodique Bibliothèque principale Documentaires Disponible Fourier cosine series method for solving the generalized thin-walled column buckling problem for Dirichlet boundary conditions / Charles C. Ike in REVUE DES COMPOSITES ET DES MATERIAUX AVANCES, Vol. 29, N° 3 (06/2019)
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Titre : Fourier cosine series method for solving the generalized thin-walled column buckling problem for Dirichlet boundary conditions Type de document : texte imprimé Auteurs : Charles C. Ike, Auteur ; Hyginus N. Omah, Auteur ; Benjamin O. Mama, Auteur ; Clifford U. Nwoji, Auteur ; Edwin U. Ikwueze, Auteur Année de publication : 2019 Article en page(s) : p. 131-137 Note générale : Bibliogr. Langues : Anglais (eng) Tags : 'Méthode des séries en cosinus de Fourier' 'Problème flambement généralisé poteaux élastiques à parois minces' 'Equation caractéristique' valeurs propres algébriques' 'Valeur propre' 'Fonctions déplacement modal' 'Charge critique' Index. décimale : 620.11 Matériaux (propriétés, résistance) Résumé : The Fourier cosine series method was used to obtain solutions to the generalized elastic thin-walled column buckling problem for the case of Dirichlet end boundary conditions. The problem is a boundary value problem given by a set of three coupled ordinary differential equations with three unknown displacement functions, and subject to the Dirichlet end boundary conditions. By choosing the origin of the longitudinal coordinate at the middle of the column, the Fourier cosine series was found to be a suitable shape function for the problem and hence the three displacement modal functions were represented using Fourier cosine series, with unknown modal amplitudes. The Fourier cosine series representation of the unknown displacement modal functions simplified the problem to an algebraic eigenvalue problem given by a set of homogenous algebraic equations whose nontrivial solution yielded the characteristic buckling equation. The stability equation was obtained as a third-degree polynomial for the asymmetric cross-sectioned column. For asymmetric cross-sections, the buckling modes were obtained as coupled flexural-torsional modes. For bisymmetric cross-sections, the buckling modes were uncoupled and failure could be flexural or flexural-torsional. For monosymmetric cross-sections, one of the buckling modes is uncoupled while the others are coupled ; and failure could be by either Euler bending or bending-torsional buckling. The solutions obtained in this work agree with results obtained by previous researchers. Note de contenu : - THEORETICAL FRAMEWORK
- METHOD : Dirichlet boundary conditions and Fourier cosine series for the buckling mode functions - Application of the Fourier cosine series method
- RESULTS : Reduction to algebraic eigenvalue problem - Special cases of the generalised elastic thin-walled column buckling problemDOI : https://doi.org/10.18280/rcma.290301 En ligne : https://www.iieta.org/download/file/fid/17476 Format de la ressource électronique : Permalink : https://e-campus.itech.fr/pmb/opac_css/index.php?lvl=notice_display&id=34858
in REVUE DES COMPOSITES ET DES MATERIAUX AVANCES > Vol. 29, N° 3 (06/2019) . - p. 131-137[article]Réservation
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Code-barres Cote Support Localisation Section Disponibilité 22406 - Périodique Bibliothèque principale Documentaires Disponible Modified single finite Fourier cosine integral transform method for finding the critical elastic buckling loads of first order shear deformable beams with fixed ends / Charles C. Ike in REVUE DES COMPOSITES ET DES MATERIAUX AVANCES, Vol. 29, N° 6 (12/2019)
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Titre : Modified single finite Fourier cosine integral transform method for finding the critical elastic buckling loads of first order shear deformable beams with fixed ends Type de document : texte imprimé Auteurs : Charles C. Ike, Auteur ; Clifford U. Nwoji, Auteur ; Hyginus N. Onah, Auteur ; Benjamin O. Mama, Auteur ; Michael E. Onya, Auteur Année de publication : 2019 Article en page(s) : p. 357-362 Note générale : Bibliogr. Langues : Français (fre) Tags : 'Equation de flambement caractéristique' 'Charge critique élastique' 'Problème valeur propre' 'Théorie des poutres déformation par cisaillement du premier ordre' 'méthode transformation intégrale en cosinus Fourier finie simple modifiée' Index. décimale : 620.11 Matériaux (propriétés, résistance) Résumé : This paper proposes a novel modified single finite Fourier cosine integral transform, which determines the elastic buckling loads of moderately-thick, fixed-end beams made of homogeneous, isotropic, linear elastic materials. First, such a beam was modelled with a fourth-order ordinary differential equation, according to the first-order shear deformation theory. Then, the single finite Fourier cosine integral transform was modified to satisfy all the boundary conditions at the fixed ends,using the apriori knowledge, and provide an exact buckling mode (shape) function for the beam. Through the modified transform, the boundary value problem was converted to an algebraic eigenvalue problem, which canbe described by a set of homogeneous algebraic equations. For nontrivial solutions, the characteristic buckling equation was drived from the vanishing of the determinant of the coefficient matrix. Solving the characteristic buckling equation, the authors obtained the eigenvalues and thus derived the buckling loads. The critical buckling load was found to correspond to the first buckling mode. The proposed modified transform gave exact expressions for the buckling loads and the critical buckling load of the fixed ends, because the integral kernel function satisfies all the boundary conditions, and the transform on the domain governing equation satisfies all the domain equations. The solutions of our method agree well with the previous studies. Note de contenu : - THEORY : Assumptions - Displacement components - Strain field components - Stress fields - Total potential energy functional, π
- METHODDOI : https://doi.org/10.18280/rcma.290603 En ligne : https://www.iieta.org/download/file/fid/21501 Format de la ressource électronique : Permalink : https://e-campus.itech.fr/pmb/opac_css/index.php?lvl=notice_display&id=34947
in REVUE DES COMPOSITES ET DES MATERIAUX AVANCES > Vol. 29, N° 6 (12/2019) . - p. 357-362[article]Réservation
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Code-barres Cote Support Localisation Section Disponibilité 22409 - Périodique Bibliothèque principale Documentaires Disponible Les risques électrostatiques : charges et décharges électrostatiques / Jean-Michel Dien in L'ACTUALITE CHIMIQUE, N° 344 (09/2010)
PermalinkScattering from shear-ordered dispersions / H. Versmold in APPLIED RHEOLOGY, Vol. 17, N° 1 (2007)
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