Lab

Emmanuel Foltête's Lab

Featured research (2)

Vibro-impact (VI) based control strategies exploit non-linear phenomena occurring during impacts between oscillating masses and vibrating structures to mitigate vibrations. They are known to be effective on a wide frequency range, in harsh environnement, and they are eco-friendly in comparison to some visco-elastic polymers used for the same application. Different assumptions emerge to explain energy dissipation such as material and contact effects, or dynamic energy transfers between the structure and the oscillating masses acting as non-linear absorbers. As classical vibratory measurement tools do not allow to accurately and easily measure what happens in the contact area and the motion of the absorber, it is difficult to validate and quantify the phenomenon. The purpose of the study is to take advantage of full field measurements of the vibro-impact phenomenon to characterise a vibro-impact absorber and to better understand the interactions occurring during impact. To reach this objective, a dedicated experimental set-up has been designed and a method involving Digital Image Correlation (DIC) and a high-speed camera is used to capture and reconstruct the motion of the oscillating mass. The characterisation allows to estimate the Coefficient Of Restitution (COR) and friction forces, and provides data that are used in two different contact modelling strategies based on the COR and on the Hertz contact theory. The quantities identified in this paper enable to better understand the physical phenomena at stakes in a VI absorber.
The aim of this work is to characterize the mechanical parameters governing the in-plane behavior of human skin and, in particular, of a keloid-scar. We consider 2D hyperelastic bi-material model of a keloid and the surrounding healthy skin. The problem of finding the optimal model parameters that minimize the misfit between the model observations and the in vivo experimental measurements is solved using our in-house developed inverse solver that is based on the FEniCS finite element computational platform. The paper focuses on the model parameter sensitivity quantification with respect to the experimental measurements, such as the displacement field and reaction force measurements. The developed tools quantify the significance of different measurements on different model parameters and, in turn, give insight into a given model's ability to capture experimental measurements. Finally, an a priori estimate for the model parameter sensitivity is proposed that is independent of the actual measurements and that is defined in the whole computational domain. This estimate is primarily useful for the design of experiments, specifically, in localizing the optimal displacement field measurement sites for the maximum impact on model parameter inference.

Lab head

Emmanuel Foltête
Department
  • Department of Applied Mechanics
About Emmanuel Foltête
  • Emmanuel Foltête received the PhD in Mechanical Engineering from the University of Franche-Comté, France in 1998. In 2000, he became Associate Professor at the Faculty of Sciences and Technology. Since 2009, he is full Professor at FEMTO ST Institute in the group of Structural Dynamics and Vibroacoustics. His main research interests are linear and nonlinear experimental identification of structural dynamics and vibroacoustics, smart materials and structures, energy harvesting.

Members (23)

Thierry Barriere
  • Institut FEMTO-ST
Morvan Ouisse
  • Institut FEMTO-ST
Scott Cogan
  • University of Franche-Comté
Vincent Placet
  • University of Franche-Comté
Najib Kacem
  • Institut FEMTO-ST
V. Blondeau-Patissier
  • Institut FEMTO-ST
Nathalie Boudeau
  • Institut FEMTO-ST
Emmanuelle Jacquet
  • University of Franche-Comté
Mohamed Assoul
Mohamed Assoul
  • Not confirmed yet
Mohamed Assoul
Mohamed Assoul
  • Not confirmed yet
Eric Joseph
Eric Joseph
  • Not confirmed yet
A Khelif
A Khelif
  • Not confirmed yet
A Khelif
A Khelif
  • Not confirmed yet
Michel Pierronnet
Michel Pierronnet
  • Not confirmed yet
Aboubakry Agne
Aboubakry Agne
  • Not confirmed yet
Agne Aboubabky
Agne Aboubabky
  • Not confirmed yet