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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Contribution à l'évaluation des efforts de coupe avec applications au fraisage de finition / Contribution to the evaluation of cutting forces with applications to finishing milling

Delahaye, Nicolas 21 May 2015 (has links)
L’usinage tient une place considérable dans l’industrie, c’est un des procédés les plus répandu. A ce titre, la maitrise du procédé de fraisage, notamment lors d’une opération de finition, est devenu un enjeu majeur dans le secteur industriel. La compréhension des phénomènes physiques présents lors d’un usinage de finition est un facteur important pour l’optimisation d’un procédé de fabrication par enlèvement de matière.Afin de déterminer les paramètres influents lors d’un usinage de finition, notamment lors d’un fraisage de profil, une nouvelle méthodologie expérimentale sera développée. Ces travaux vont s’articuler autour de trois activités principales :- La mise en place d’une instrumentation capable de recueillir une image des efforts de coupe. Ce dispositif expérimental devra être équipé de capteurs et d’une chaine d’acquisition pour acquérir les composantes des efforts selon les directions x et y.- Le développement d’un nouveau dispositif passe par une étape qualification dans laquelle une série de tests permettra d’établir la capabilité du montage.- Cette étude expérimentale s’accompagne d’une campagne d’essais permettant de définir les paramètres les plus influents lors d’un fraisage de profil de finition. / Machining holds an important place in the industry, this is one the most common process. As thus, mastering the milling process, especially during a finishing operation, has become a major issue in the insdustrial sector. Understanding the physical phenomena present in a finishing machining is an important factor for the optimization of a manufacturing process by removing material.In order to determine the most important factors during a finishing machining, in particular during a profile milling, a new experimental methodology will be developed. This work will focus on three main activities :- The introduction of instrumentation capable of collecting an image cutting forces. This experimental device must be equipped with sensors and an acquisition channel to acquire the components of the forces in the x and y directions.- The development of a new device going through a stage qualification in which a series of tests will establish the capability of experimental device.- This experimental study is accompanied by a series of tests to define the most important parameters in a finishing profile milling
2

[pt] CARACTERIZAÇÃO FÍSICA, QUÍMICA, MINERALÓGICA E MICROMORFOLÓGICA DO SOLO MOLE DO PORTO DE SANTANA, NO AMAPÁ / [en] PHISICAL, CHEMICAL, MINERALOGICAL AND MICROMORFOLOGICAL CHARACTERIZATION OF THE SOFT SOIL OF PORT OF SANTANA, IN AMAPA

12 September 2017 (has links)
[pt] Um grande movimento de massa do tipo deslizamento seguido de fluxo de solo, ocorrido em 28 de março de 2013 no Porto de Santana, na região da foz do Rio Amazonas, no Amapá, motivou o estudo das características do solo local, cujo comportamento na ruptura foi semelhante ao dos solos sensíveis da Escandinávia e do leste do Canadá, deslocando-se como um fluido-viscoso e alcançando grandes distâncias no fundo do rio. Para procurar entender o comportamento do material, o presente trabalho propôs extenso programa experimental objetivando a caracterização física, química, mineralógica e micromorfológica do material. Resultados de ensaios de campo relativos às amostras de solo estudadas são apresentados e os métodos de classificação de solos sensíveis, estabelecidos no meio geotécnico, são discutidos sobre sua eficiência. O trabalho apresenta resultados de ensaios físicos, incluindo ensaios de sensibilidade com cone sueco e ensaios de caracterização geotécnica convencional de laboratório; ensaios químicos de composição dos grãos, de capacidade de troca catiônica, pH e porcentagem de matéria orgânica; de composição iônica, condutividade elétrica e salinidade da água dos poros do solo; ensaios mineralógicos de difração de raios X; e ensaios de visualização da micromorfologia dos solos com microscopia eletrônica de varredura e detector de dispersão de energia. Os resultados obtidos permitiram identificar sensibilidades elevadas em algumas das amostras ensaiadas, assim como algumas causas de seu desenvolvimento. / [en] A large mass movement like flow-sliding of soil, occurred in March 28, 2013 at the Port of Santana, in the region of the mouth of the Amazon River in Amapá, led to the study of the local soil characteristics, whose behavior at rupture was similar to the sensitive soils from Scandinavia and eastern Canada, moving like a viscous fluid and reaching long distances on the river bottom. To try to understand the behavior of the material, this paper has proposed extensive experimental program aimed at the physical, chemical, mineralogical and micromorphological characterization of the material. Field tests results on soil samples studied are presented and the sensitive soil classification methods established in the geotechnical environment are discussed about its efficiency. The paper presents results of physical tests, including sensitivity tests with Swedish fall-cone and conventional laboratory geotechnical characterization tests; chemical tests of grain composition, cation exchange capacity, pH and percentage of organic matter; ion composition, conductivity electrical and salinity of pore water of soil; mineralogical tests with X-ray diffraction, micromorphology viewing tests of soils with scanning electron microscopy and energy dispersive detector. The results have identified high sensitivities in some of the test samples, as well as some causes of its development.

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