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M I N I S T E R E D E L ’ E N S E I G N E M E N T S U P E R I E U R E T D E L A R E C H E R C H E S C I E N T I F I Q U E UNIVERSITE DJILLALI LIABES SIDI BEL ABBES

F A C U L T E D E S S C I E N C E S D E L ’ I N G E N I E U R

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Résumé :

Dans cette thèse, le flambement mécanique des plaques en matériaux fonctionnement graduels (FGM) est concèderai en utilisant une nouvelle classe des théories des plaques à quatre variable. Contrairement aux autres théories, le nombre d’inconnues impliquées est de quatre alors que les autres théories de déformation de cisaillement nécessite cinq variables .cette présente théorie n’a pas besoin des coefficients de correction de cisaillement et donne une variation parabolique des contraintes de cisaillement transversal à travers l’épaisseur en satisfaisant l’annulation de la contrainte de cisaillement aux surfaces extrême de la plaque .les propriétés matérielles de la plaque sont supposée être varier à traver l’épaisseur selon une loi de puissance .De plus le flambement thermique des plaques (FGM) a été aussi étudié en utilisant une approche simple est efficace basée sur la théorie classique des plaques et la théorie de premier ordre.

Mots clés :

FGM, déformation, plaques sandwiches.

Abstract

In this research, mechanical buckling of hybrid functionally graded plates is considered using a new four variable refined plate theory. Unlike any other theory, the number of unknown functions involved is only four, as against five in case of other shear deformation theories. The theory presented is variation ally consistent, does not require shear correction factor, and gives rise to transverse shear stress variation such that the transverse shear stresses vary parabolic ally across the thickness satisfying shear stress free surface conditions. The plate properties are assumed to be varied through the thickness following a simple power law distribution in terms of volume fraction of material constituents. Governing equations are derived from the principle of minimum total potential energy. The closed-form solution of a simply supported rectangular plate subjected to in-plane loading has been obtained by using the Navier method. The effectiveness of the theories is brought out through illustrative examples. In this research, mechanical buckling of hybrid functionally graded plates is considered using a new four variable refined plate theory. Unlike any other theory, the number of unknown functions involved is only four, as against five in case of other shear deformation theories. The theory presented is variation ally consistent, does not require shear correction factor, and gives rise to transverse shear stress variation such that the transverse shear stresses vary parabolic ally across the thickness satisfying shear stress free surface conditions. The plate properties are assumed to be varied through the thickness following a simple power law distribution in terms of volume fraction of material constituents. In addition, the thermal buckling of functionally graded plates is studded using a simple and affection based on classical plate theory and fist shear deformation theory. Governing equations are derived from the principle of minimum total potential energy. The closed-form solution of a simply supported rectangular plate subjected to in-plane loading has been obtained by using the Navier method. The effectiveness of the theories is brought out through illustrative examples.

Keywords :

Functionally graded materials, two-variable refined plate theory, shear deformation theory, Sandwich plate.

صخلم

ٓ ٍِ فذٖىا ر حذيذخ خيشظّ هبَؼزسبث خيصبخىا خخسذزَىا داَ٘ىا ٍِ خجمشَىا خنيَسىا حئبفصىا ٚيػ خيساشحىا خّٗشَىا ك٘يس وييحر ٕ٘ خساسذىا ٓ ر يىبؼىا تيرشزىا ٗ ٗ ِيشيغزَى ءاشخإ فيزخٍ ِيث خّسبقٍ جربَْىا يزىا زخأر ٗأ دبٕ٘شزىا لا خيدَ٘ؼىا ٚيػ ذْزسر يزىا ٗ هبخدإ دبؼيص٘زىا ، خيطخىا ، خئفبنَىا ، خيؼطقىا ، خيسلآا خيجيدىا ٗ هبدٍ لَس ٚيػ خحاصلإا . ٚيػ دبيشظّ فلاخ ٙشخأ ، دذػ طقف ٌٕ خحشزقَىا خيشظْىا يف خفٗشؼٍ شيغ هاٗذىا خؼثسأ ، خسَخ ِيح يف ٗأ شثمأ دلابح يف ٙشخأ صقىا ٓ٘شر دبيشظْى يضشؼىا . خيشظْىا ٔجشر داشيغزَىا خقسبْزٍ خحشزقَىا خيشظْىا خينيسلانىا يطؼرٗ صقىا حيحصر وٍبؼٍ تيطزر لا حذيذػ تّا٘خ يف حئبفصيى بَْيث لَسىا هلاخ ٍِ يضشؼىا صقىا دادبٖخلاى بئفبنٍ بفصٗ د خحيفصيى خييفسىا ٗ خي٘يؼىا فا٘ح ٚيػ ًذؼْر يزىاٗ يضشؼىا صقىا دادبٖخلاا ٚيػ طٗششىا ققح . ٍِ ِيػّ٘ خساسد ذَر خجمشَىا حئبفصىا خيصبخىا خخسذزٍ داَ٘ىا ٍِ ( » عّ٘ أ : خيصبخىا خخسذزٍ حدبٍ / ليٍاشيس / خيصبخىا خخسذزٍ حدبٍ « ; » ة عّ٘ : ليٍاشيس / خيصبخىا خخسذزٍ حدبٍ / ُذؼٍ « ) . ضشفّ ُأ دلاٍبؼٍ خّٗشَىا ٗ خجسّ ُ٘سا٘ث ٗ دلاٍبؼٍ غيص٘زىا قفٗ لَسىا ٓبدرا يف عبطقّا ُٗذث شيغزر خجمشَىا خحيفصيى ذٖدىا نوناقل عيزوتلا ةللاذب يف دوذح ةلاد مجحلا دبّ٘نَيى . بْيَؼزسا حذػ عاّ٘أ خجمشَىا حئبفصىا ٍِ زخأث ٗأ خقجط وم لَسٗ خحيفصىا وثبَر لا . بٖييػ وصحزَىا حئبزْىا خحشزقَىا خيشظْىبث ( غٍ خؼثسأ ويٕبدٍ ) دبيشظْىا ٗ ٙشخلأا ر يىبؼىا تيرشزىا ٗ ٓ٘شزيى يضشؼىا صقىا يف ( ويٕبدٍ خسَخ ٗأ شثمأ ) دبنر د خقثبطزٍ ُ٘م . صيخزسّ ُأ خّٗشَىا ك٘يس وحى خطيسثٗ خقيقد خحشقَىا خيشظْىا خيصبخىا خخسذزَىا داَ٘ىا حئبفص ءبْحّلا .

تاملك

هيحاتفم

:

خيصبخىا خخسذزَىا داَ٘ىا يىبؼىا تيرشزىا خيشظّ ، ِيشيغزَى ، يضشؼىا صقىا ٓ٘شر خيشظّ ، خجمشَىا حئبفصىا .

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