Emmanuelle Vidal-Salle

Bio: Emmanuelle Vidal-Salle is an academic researcher from University of Lyon. The author has contributed to research in topics: Constitutive equation & Forming processes. The author has an hindex of 23, co-authored 102 publications receiving 2480 citations. Previous affiliations of Emmanuelle Vidal-Salle include Institut national des sciences Appliquées de Lyon & Centre national de la recherche scientifique.

Experimental and numerical analyses of textile reinforcement forming of a tetrahedral shape

Abstract: An experimental device for textile composite reinforcement forming is presented. A strongly double curved tetrahedral shape is formed by punch and die. This shape is those of the corner fitting parts used as corner brackets. The device shows that is possible to obtain such geometry by punch and die forming thanks to strong blank holder loads and an appropriate reinforcement. There is no wrinkle in the tetrahedral part of the formed shape but the six blank holders create wrinkles in the plane part of the preform. The shear angles reach 60° but there is no wrinkling in this zone. The presented forming process enables the experimental validation of a semi-discrete simulation approach. It is shown that shear angles and wrinkle shapes obtained by this numerical approach are in good agreement with the forming experiment. The computation of the shape of wrinkles after forming is necessary to check that these wrinkles do not expand to the useful part of the preform. This needs to take the bending stiffnesses into account. This is not the case when the simulation is based on a membrane approach.

Quantitative X-ray tomography

Abstract: X-ray computer tomography (CT) is fast becoming an accepted tool within the materials science community for the acquisition of 3D images. Here the authors review the current state of the art as CT transforms from a qualitative diagnostic tool to a quantitative one. Our review considers first the image acquisition process, including the use of iterative reconstruction strategies suited to specific segmentation tasks and emerging methods that provide more insight (e.g. fast and high resolution imaging, crystallite (grain) imaging) than conventional attenuation based tomography. Methods and shortcomings of CT are examined for the quantification of 3D volumetric data to extract key topological parameters such as phase fractions, phase contiguity, and damage levels as well as density variations. As a non-destructive technique, CT is an ideal means of following structural development over time via time lapse sequences of 3D images (sometimes called 3D movies or 4D imaging). This includes information nee...

Characterization of mechanical behavior of woven fabrics: Experimental methods and benchmark results

Abstract: Textile composites made of woven fabrics have demonstrated excellent mechanical properties for the production of high specific-strength products. Research efforts in the woven fabric sheet forming are currently at a point where benchmarking will lead to major advances in understanding both the strengths and the limitations of existing experimental and modeling approaches. Test results can provide valuable information for the material characterization and forming process design of woven composites if researchers know how to interpret the results obtained from varying test methods appropriately. An international group of academic and industry researchers has gathered to design and conduct benchmarking tests of interest to the composite sheet forming community. Shear deformation is the dominative deformation mode for woven fabrics in forming; therefore, trellis-frame (picture-frame) and bias-extension tests for both balanced and unbalanced fabrics have been conducted and compared through this collaborative effort. Tests were conducted by seven international research institutions on three identical woven fabrics. Both the variations in the setup of each research laboratory and the normalization methods used to compare the test results are presented and discussed. With an understanding of the effects of testing variations on the results and the normalization methods, numerical modeling efforts can commence and new testing methods can be developed to advance the field.