ETUDE DES MODES DE DEFORMATION D'ALLIAGES D'ALUMINIUM SOUS SOLLICITATIONS MONOTONE ET CYCLIQUES (CHARGEMENTS PROPORTIONNELS ET NON PROPORTIONNEL) PDF Download

Author: LAURENCE.. HAUTEFEUILLE-BEYLAT
Publisher:
ISBN:
Category :
Languages : fr
Pages :

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Book Description
LE COMPORTEMENT MECANIQUE DE DEUX ALLIAGES D'ALUMINIUM EST ETUDIE. L'ALLIAGE 2091 EST UN ALLIAGE QUATERNAIRE AL-LI-CU-MG. LES PRINCIPAUX ELEMENTS D'ADDITION DE L'ALLIAGE 2024 SONT LE CUIVRE ET LE MAGNESIUM. L'ANALYSE DES PHASES PRECIPITEES ET LES MODES DE DEFORMATION SOUS CHARGEMENT MONOTONE, PERMET D'EXPLIQUER L'EVOLUTION DE LA TENACITE DE CES ALLIAGES EN FONCTION DES TRAITEMENTS THERMIQUES. LE COMPORTEMENT ET LA STRUCTURE DE DISLOCATIONS DES ALLIAGES A L'ETAT SOUS-VIEILLI SONT ENSUITE CARACTERISES LORS D'UNE SOLLICITATION CYCLIQUE DE TRACTION-COMPRESSION. LORS D'UNE SOLLICITATION MULTIAXIALE DE L'ALLIAGE 2024 T3, L'APPARITION D'UNE NOUVELLE STRUCTURE DE DISLOCATIONS MET EN EVIDENCE L'IMPORTANCE DU TRAJET DE CHARGEMENT

Author: Veronique Ferney
Publisher:
ISBN:
Category :
Languages : fr
Pages : 461

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Ce travail est centré autour de l'étude du comportement en fatigue multiaxiale de deux alliages a durcissement structural: un alliage d'aluminium, le 2024, et un superalliage base nickel, le waspaloy. Afin de mettre en évidence l'influence de la microstructure sur le comportement mécanique, ces deux alliages sont sollicites dans deux états de précipitation, sous-vieilli et survieilli, sous chargements proportionnels et non proportionnels. L'écrouissage est interprété dans chaque cas en termes de composantes isotrope et cinématique, en relation avec les structures de dislocations observées. Dans le cas du waspaloy à l'état sous-vieilli, l'importance de la simultanéité de l'activation des systèmes de glissement sur la nature cinématique de l'écrouissage est mise en évidence. Enfin, dans un dernier temps, l'endommagement des deux alliages est étudié sous chargements proportionnel et non proportionnel.

Author: Agnes Buka
Publisher: World Scientific
ISBN: 1848167997
Category : Science
Languages : en
Pages : 299

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The book intends to give a state-of-the-art overview of flexoelectricity, a linear physical coupling between mechanical (orientational) deformations and electric polarization, which is specific to systems with orientational order, such as liquid crystals. Chapters written by experts in the field shed light on theoretical as well as experimental aspects of research carried out since the discovery of flexoelectricity. Besides a common macroscopic (continuum) description the microscopic theory of flexoelectricity is also addressed. Electro-optic effects due to or modified by flexoelectricity as well as various (direct and indirect) measurement methods are discussed. Special emphasis is given to the role of flexoelectricity in pattern-forming instabilities. While the main focus of the book lies in flexoelectricity in nematic liquid crystals, peculiarities of other mesophases (bent-core systems, cholesterics, and smectics) are also reviewed. Flexoelectricity has relevance to biological (living) systems and can also offer possibilities for technical applications. The basics of these two interdisciplinary fields are also summarized.

Author: Jerome V. Moloney
Publisher: Springer Science & Business Media
ISBN: 9780387985817
Category : Business & Economics
Languages : en
Pages : 270

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Book Description
Mathematical methods play a significant role in the rapidly growing field of nonlinear optical materials. This volume discusses a number of successful or promising contributions. The overall theme of this volume is twofold: (1) the challenges faced in computing and optimizing nonlinear optical material properties; and (2) the exploitation of these properties in important areas of application. These include the design of optical amplifiers and lasers, as well as novel optical switches. Research topics in this volume include how to exploit the magnetooptic effect, how to work with the nonlinear optical response of materials, how to predict laser-induced breakdown in efficient optical devices, and how to handle electron cloud distortion in femtosecond processes.