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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

Etude d'un emmanchement fretté compte tenu de l'effet combiné des défauts de forme et d'état de surface / Study of shrink fitting considering the combined effect of phase defects and surface roughness

Boutoutaou, Hamid 24 January 2012 (has links)
Le but principal de cette thèse est de présenter deux contributions dans le domaine desassemblages frettés en prenant en considération les défauts de forme et d’état de surface. Lapremière contribution concerne l’étude de l’influence du défaut de forme sur les caractéristiquesdes assemblages frettés en utilisant une approche basée sur la modélisation par éléments finis.Nous avons constaté que ce défaut a une influence notable sur la résistance de l’assemblage. Destravaux déjà réalisés dans le laboratoire de mécanique de l’université de Bourgogne ont étéconfirmés. Dans la deuxième contribution, nous avons proposé d’intégrer les défauts d’état desurface (rugosité) en créant un élément fini homogénéisé d’interface. Cette technique nous afacilité le maillage de l’interface formés par de macro-éléments traduisant le comportement desaspérités. Ce comportement particulier, dépend de plusieurs paramètres mécaniques etgéométriques qui ont été pris en compte pour définir et identifier numériquement une loid’élasticité isotrope transverse. Cette nouvelle loi a permis de simuler correctement lesassemblages frettés en prenant en compte le défaut d’état de surface. Les résultats obtenus ont étéconfrontés aux expérimentations. En fin, une méthodologie de conception des spécifications dufrettage en considérant le processus d’élaboration des surfaces a été proposée. / The main purpose of this thesis is to present two contributions in the field of shrink fitassembly taking into account the defects of form and roughness surfaces. The first contributionconcerns the study of the influence of the defect forme on the characteristics of shrinked assemblyusing an approach based on finite element modeling. We found that this defect has a significantinfluence on the resistance of the assembly. The work already done in the laboratory of mechanicsat the University of Bourgogne have been confirmed. In the second contribution, we proposed tointegrate the surface defects (roughness) by creating a homogenized finite element interface. Thistechnique has facilitated the mesh of the interface formed by the macro-elements reflecting thebehavior of the asperities. This particular behavior, depends on several mechanical andgeometrical parameters that have been taken into account in defining and identifying a digitallytransverse isotropic elastic law. The new law was used to simulate properly shrinked assembliestaking into account the defect of roughness surface. The results were compared withexperiments. In the end, a design methodology specification by considering the shrinking processof surfaces has been proposed
2

An Analysis of Strain and Displacement within Elastically Averaged Electromagnetic Formed Joints

Sattler, Andrew M. 18 May 2015 (has links)
No description available.
3

Testing and Analysis of Innovative High-Speed Automotive Fastening System for Multi Materials

Srinivaas, Sujith 08 October 2020 (has links)
No description available.
4

Adheze spojů asfaltových pásů mechanicky kotvených / Adhesion connections asphalt strips mechanically fastened

Petříček, Tomáš Unknown Date (has links)
One-layer mechanical fastening waterproofing systems are often used within the compositions of flat roofs. Although in case of plastic based systems it is a common solution, for asphalt felts it handles about a relatively new approach, since the application of asphalt has a long history in the building industry. There are some key factors which all of the one-layer mechanically fastening systems should meet, especially water-resistance and resistance against the suction of wind. The application of dynamic loads on the joints may damage the bonds, which may lead to leakage of water. In particular the most delicate locations are the anchoring points at places where the waterproofing sheets are not connected mutually and the wind is captured. The characteristics of mechanically fastening waterproofing membranes may be verified by a specific test which is able to simulate the winds suction force, nonetheless it is quite expensive. Throughout the solution of the presented work an equipment was designed to observe the behaviour of roof compositions on smaller segments while taking into account the fastening elements, thus bringing the results closer to reality. In the first phase the presented dissertation aims to look at the possibilities of comparison of mechanically fastening bitumen reinforced sheets in a way, that they would show the extent to which the joints depend on the parameters of bitumen sheet - like the quality of the bitumen mass, the type bearing linen, the thickness of the layer or just the width of strip overlap. In the next phase the research was focused on the extent at which the strength of the resulting mechanically fastened joints is affected by the placement of fastenings elements within the strip overlap, including the possibilities when the distances from the edges of the bitumen strip cannot be maintained or because of improper geometry of fastening elements. The measurements were performed on both variants of flat roofs, thermally insulated

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