Modélisation de l'influence des défauts de surface sur le comportement en fatigue de nuances d'acier innovantes PDF Download

Author: Wichian Niamchaona
Publisher:
ISBN:
Category :
Languages : fr
Pages : 0

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L'innovation de l'industrie métallurgique des aciers pour le secteur automobile passe par la fabrication de nuances d'acier à haute résistance telle que le grade CP800. Les nuances d'acier sont très sensibles, du point de vue de leur comportement en fatigue, à la présence d'un défaut de surface comme ceux générés par la mise en forme des pièces ou par la découpe des tôles. Des défauts de plusieurs types et de différentes tailles, similaires à ceux rencontrés lors du poinçonnage ou de l'emboutissage des tôles, ont été reproduits par électroérosion sur des éprouvettes de la nuance d'acier CP800. Ces éprouvettes font l'objet de notre étude en fatigue sur les plans numérique et expérimental. La modélisation de l'influence de ces défauts en fatigue utilise les deux approches globale et de type plan critique de la fatigue multiaxiale, et avec prise en compte du gradient des contraintes.La simulation numérique vise à établir les champs des contraintes et leurs gradients au voisinage des défauts analysés expérimentalement. La prise en compte des gradients des contraintes permet aux critères de fatigue multiaxiaux une prévision du comportement réel en fatigue beaucoup plus juste de cette nuance d'acier en présence de défauts de surface. Prendre en compte l'influence du gradient de contrainte est indispensable pour une prévision correcte de la limite de fatigue du matériau à haute résistance en présence d'un défaut de petite taille.

Author: Benjamin Gerin
Publisher:
ISBN:
Category :
Languages : fr
Pages : 0

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Cette étude fait partie du projet ANR DEFISURF, avec pour objectif d'identifier et de modéliser les divers effets de la surface sur la tenue en fatigue de composants forgés. Deux composants sont étudiés: une éprouvette extrudée à froid et une bielle estampée à chaud et nettoyée de sa calamine par grenaillage (shot-blasting). Pour chaque composant, différents lots sont étudiés afin de quantifier l'effet des procédés sur les caractéristiques mécaniques et sur le comportement en fatigue. Deux taux de corroyage différents sont utilisés pour l'extrusion à froid. Pour les bielles, différents grenaillages sont réalisés pour obtenir divers états de surface.Les différents lots sont caractérisés de façon approfondie et des essais de fatigue sont effectués. Des essais de fatigue en traction, torsion et flexion plane sont réalisés sur les éprouvettes extrudées. Des éprouvettes de fatigue sont prélevées dans l'âme des bielles et sollicitées en flexion plane.En extrusion à froid, les aspects les plus influents en fatigue sont la prédéformation subie lors de la mise en forme (taux de corroyage) et les contraintes résiduelles. En forgeage à chaud, ce sont les défauts de forgeage en surface et les contraintes résiduelles introduites par le grenaillage qui ont le plus d'influence.Une modélisation en fatigue est proposée pour chaque composant. Pour l'extrusion, un critère de fatigue multiaxial permet de prendre en compte les différents types de chargement ainsi que l'effet des contraintes résiduelles. Pour les bielles deux approches sont utilisées. La première est une analyse de la géométrie des défauts qui utilise un demi-ellipsoïde pour approximer leur forme. La deuxième approche est une simulation numérique par éléments finis des défauts critiques. Les contraintes résiduelles sont intégrées dans les simulations avec un critère multiaxial. Les simulations permettent de retrouver les résultats expérimentaux avec une erreur d'environ 15%.

Author: International Atomic Energy Agency
Publisher: International Atomic Energy Agency
ISBN: 9789201063205
Category : Technology & Engineering
Languages : en
Pages : 72

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This publication results from a technical meeting on phenomenology and technologies relevant to in-vessel melt retention (IVMR) and ex-vessel corium cooling (EVCC). The purpose of the publication is to capture the state of knowledge, at the time of that meeting, related to phenomenology and technologies as well as the challenges and pending issues relevant to IVMR and EVCC for water cooled reactors by summarizing the information provided by the meeting participants in a form useful to practitioners in Member States.

Author: Jonathan Cross
Publisher: Cambridge University Press
ISBN: 9780521663779
Category : Biography & Autobiography
Languages : en
Pages : 348

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Stravinsky's work spanned the major part of the twentieth century and engaged with nearly all its principal compositional developments. This Companion reflects the breadth of Stravinsky's achievement and influence in essays by leading international scholars on a wide range of topics. It is divided into three parts dealing with the contexts within which Stravinsky worked (Russian, modernist and compositional), with his key compositions (Russian, neoclassical and serial), and with the reception of his ideas (through performance, analysis and criticism). The volume concludes with an interview with the leading Dutch composer Louis Andriessen and a major re-evaluation of 'Stravinsky and Us' by Richard Taruskin.

Author: Stephen Walsh
Publisher: Knopf
ISBN: 0593319044
Category : Biography & Autobiography
Languages : en
Pages : 720

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Book Description
Widely regarded the greatest composer of the twentieth century, Igor Stravinsky was central to the development of modernism in art. Deeply influential and wonderfully productive, he is remembered for dozens of masterworks, from The Firebird and The Rite of Spring to The Rake's Progress, but no dependable biography of him exists. Previous studies have relied too heavily on his own unreliable memoirs and conversations, and until now no biographer has possessed both the musical knowledge to evaluate his art and the linguistic proficiency needed to explore the documentary background of his life--a life whose span extended from tsarist Russia to Switzerland, France, and ultimately the United States. In this revealing volume, the first of two, Stephen Walsh follows Stravinsky from his birth in 1882 to 1934. He traces the composer's early Russian years in new and fascinating detail, laying bare the complicated relationships within his family and showing how he first displayed his extraordinary talents within the provincial musical circle around his teacher, Nikolay Rimsky-Korsakov. Stravinsky's brilliantly creative involvement with the Ballets Russes is illuminated by a sharp sense of the internal artistic politics that animated the group. Portraying Stravinsky's circumstances as an émigré in France trying to make his living as a conductor and pianist as well as a composer while beset by emotional and financial demands, Walsh reveals the true roots of his notorious obsession with money during the 1920s and describes with sympathy the nature of his long affair with Vera Sudeykina. While always respecting Stravinsky's own insistence that life and art be kept distinct, Stravinsky makes clear precisely how the development of his music was connected to his life and to the intellectual environment in which he found himself. But at the same time it demonstrates the composer's remarkably pragmatic psychology, which led him to consider the welfare of his art to be of paramount importance, before which everything else had to give way. Hence, for example, his questionable attitude toward Hitler and Mussolini, and his reputation as a touchy, unpredictable man as famous for his enmities as for his friendships. Stephen Walsh, long established as an expert on Stravinsky's music, has drawn upon a vast array of material, much of it unpublished or unavailable in English, to bring the man himself, in all his color and genius, to glowing life. Written with elegance and energy, comprehensive, balanced, and original, Stravinsky is essential reading for anyone interested in the adventure of art in our time. Praise from the British press for Stephen Walsh's The Music of Stravinsky "One of the finest general studies of the composer." --Wilfrid Mellers, composer, Times Literary Supplement "The beautiful prose of The Music of Stravinsky is itself a fund of arresting images. For those who already love Stravinsky's music, Walsh's essays on each work will bring a smile of recognition and joy at new kernels of insight. For those unfamiliar with many of the works he discusses, Walsh's commentaries are likely to whet appetites for performances of the works." --John Shepherd, Notes "This book sent me scurrying back to the scores and made me want to recommend it to other people. Above all, it is a good read." --Anthony Pople, Music and Letters

Author: Michael Panik
Publisher: CRC Press
ISBN: 1420091980
Category : Mathematics
Languages : en
Pages : 832

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Regression Modeling: Methods, Theory, and Computation with SAS provides an introduction to a diverse assortment of regression techniques using SAS to solve a wide variety of regression problems. The author fully documents the SAS programs and thoroughly explains the output produced by the programs.The text presents the popular ordinary least square

Author:
Publisher:
ISBN: 9780646180885
Category : Masculinity
Languages : en
Pages : 245

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Author: Judith Surkis
Publisher: Cornell University Press
ISBN: 1501729993
Category : History
Languages : en
Pages : 296

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How did marriage come to be seen as the foundation and guarantee of social stability in Third Republic France? In Sexing the Citizen, Judith Surkis shows how masculine sexuality became central to the making of a republican social order. Marriage, Surkis argues, affirmed the citizen's masculinity, while also containing and controlling his desires. This ideal offered a specific response to the problems—individualism, democratization, and rapid technological and social change—associated with France's modernity. This rich, wide-ranging cultural and intellectual history provides important new insights into how concerns about sexuality shaped the Third Republic's pedagogical projects. Educators, political reformers, novelists, academics, and medical professionals enshrined marriage as the key to eliminating the risks of social and sexual deviance posed by men-especially adolescents, bachelors, bureaucrats, soldiers, and colonial subjects. Debates on education reform and venereal disease reveal how seriously the social policies of the Third Republic took the need to control the unstable aspects of male sexuality. Surkis's compelling analyses of republican moral philosophy and Emile Durkheim's sociology illustrate the cultural weight of these concerns and provide an original account of modern French thinking about society. More broadly, Sexing the Citizen illuminates how sexual norms continue to shape the meaning of citizenship.

Author: Halcyone H. Bohen
Publisher: Philadelphia : Temple University Press
ISBN: 9780877221999
Category : Science
Languages : en
Pages : 362

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Monograph on the effects of flexible hours of work on conflicting demands of parenting and employment (esp. Of married women woman workers) in the USA - based on a survey of civil servants in Washington D.C., considers sociological aspects and psychological aspects, the influence of traditional sexual division of labour, the effect on quality of working life, child care, job satisfaction, etc., and explains research methodology (incl. Data collecting and data analysis). Bibliography pp. 257 to 329 and tables.

Author: Ran Bhamra
Publisher: CRC Press
ISBN: 1498766749
Category : Technology & Engineering
Languages : en
Pages : 220

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An eternal dilemma for all organizations, and one that a considerable portion of management schools are set up to address, is how to become and stay competitive. Organisational Resilience: Concepts, Integration, and Practice brings together, for the first time, key works that describe the scope and nature of resilience and provides direction to tak