Cédric BONNARDOT : "Contributions to the improvement of a mechanical characterization test of ultra-thin sheets by incremental microforming"

Cédric BONNARDOT PhD works : "Contributions to the improvement of a mechanical characterization test of ultra-thin sheets by incremental microforming"

The presentation will be in French. Although the defense will be public, given the sanitary measures currently in force, the defense will be dematerialized (non-presential), but it will be possible to follow the defense online through a link that will be communicated later.

Abstract : Nowadays, the desire for technology to produce smaller and smaller components is very present in industries. However, the physics governing the behavior of materials at the microscopic scale is no longer the same as at the macro scale. This is why the study of incremental microforming was developped and led to the definition of a new type of characterization test : the InDef test. This in order to identify the parameters constituting the behaviour laws of the materials tested in the form of ultra-thin sheets. However, the cost of identifying with this method is strongly linked to the numerical simulation time. This thesis is dedicated to the improvement of the InDef test by the introduction of a toolbox for parametric generation of paths based on NURBS curves. Using this type of curve, a toolpath compensation method allowing to minimize the forming defects has been obtained without the use of numerical tools. A method of taking into account geometrical defects, based on modal superposition, is also introduced to tend towards a more precise prediction of the process. The process simulation was also carried out using a Newmark implicit time integration algorithm. Finally, the development of all these tools tends to improve the generation of deformation paths using the InDef test driven by the notion of identifiability.

Jury Composition :

DELAMÉZIÈRE Arnaud          Professeur à l'INSIC St-Dié des Vosges, LEM3, Reporter

LEOTOING Lionel                   Maître de Conférences HDR à l'INSA de Rennes, Reporter

DAL SANTO Philippe             Professeur à ENSAM ParsiTech Angers, LAMPA, Reviewer

RICHARD Fabrice                  Maître de Conférences HDR à l'Université de Franche-Comté, UBFC/FEMTO-ST, Reviewer

THIBAUD Sébastien              Professeur à l'ENSMM, UBFC/FEMTO-ST, PhD Director

MALECOT Pierrick                Maître de Conférences à l'ENSMM, UBFC/FEMTO-ST, Invitee

Localization : salle transfert visioconférence de l'ENSMM (26 rue de l'Épitaphe, 25000 Besançon)