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Auteur / Autrice : Fabien Grange
Direction : Joël Rech
Type : Thèse de doctorat
Discipline(s) : Mécanique et ingénierie
Date : Soutenance en 2014
Etablissement(s) : Ecole nationale d'ingénieurs (Saint-Etienne ; 1961-....)

Mots clés

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Résumé

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Mass finishing is a group of manufacturing processes that allow large quantities of parts to be simultaneously polished including barrel finishing, vibratory finishing or drag finishing. This kind of processes is increasingly used to replace manual operations in many fields such as aerospace, medical. They lead to a fine polishing and also an increase in life time. Unfortunatly for each new part to be polished the development is empirie, based on testing, involving high costs and time. Our investigations aim to lead to the comprehension of involved mechanisms at the local scale of contacts. Experimental devices have been developed to reproduce contacts between abrasive medias and parts with different conditions. The first one give a continuous flow of medias and the second introduce a vibration of the test part, immerged under medias. They permit to follow the evolution of surface roughness and residual stress after several polishing conditions and durations. Numerical simulations have been performed with Discrete Elements Method and Finite Elements simultaions Coupled Eulerian Lagrangian in order to identify the local conditions of contacts (perssures and velocities). First, the DEM modelisations, with the real shape of medias, give realistic simulations for velocities but the rigid bodies complicate the extraction of pressures. Secondly, FE simulations reproduce fluid structure interactions, leaving out the shape and size of medias for the benefit of a behavior law. They permit to simulate a larger volume of medias and extract velocities and pressures at the interface. A wear law could be implemented to connect experimental evolutions of roughness and numerical results of pressures and velocities.