PhD Thesis Defense of Taiqu Liu from UBFC prepared at the FEMTO-ST Research Institute
Congratulations to Taiqu Liu for having successfully defended his PhD Thesis in the frame of the SSUCHY Project.
He is the third PhD student to graduate in the frame of the project. The defence took place on the 20th of January 2021, in Université de Franche-Comté (Besançon, France). So far, Taiqu Liu’s work led to 1 oral presentation in an international conference.
Taiqu Liu is now open for a a post doc, feel free to contact him!
Taiqu Liu at his PhD defense
TITLE: Multi-scale characterization of the damping of plant fiber composite materials
SUMMARY
This PhD thesis is a part of the European SSUCHY Project (H2020-BBI) which aims to develop 100% bio-based composite materials, in terms of reinforcements and matrices.
The main objective of this thesis is to provide a better characterization and understanding of damping in Plant fiber composites (PFCs) using various experimental techniques at different scales and on a wide range of frequency. This thesis starts with the review of literature on the damping behavior of PFCs. Then, the influences of many parameters including matrix types, fiber architecture, woven pattern, temperature, frequency and moisture content on the damping properties of PFCs are investigated based on dynamic mechanical analysis (DMA) and modal analysis. Furthermore, a constant amplitude method as well as constant stiffness method are used to map the in situ damping properties at the microscale based on grid dynamic Nanoindentation (DNI). These results are then compared to those obtained from dynamic mechanical analysis and modal test methods. The results from DNI show the contribution of each component (fiber, matrix and interface) on energy dissipation. Finally, the damping properties measured using these three experimental techniques at the three different scales are plotted on a wide frequency and temperature range.
JURY MEMBERS
Reporter – Mr. Alain BOURMAUD – HDR Research Engineer – IRDL Institute
Reporter – Mr. Jean-François DEU – University Professor – CNAM
Examiner – Mr. Stéphane FONTAINE – University Professor – Arts et Métiers (Metz)
Thesis Director – Mr. Morvan OUISSE – University Professor – ENSMM
Thesis co-director – Ms. Pauline BUTAUD – Lecturer – ENSMM
Thesis co-director – Mr. Vincent PLACET – HDR Research Engineer – Université Franche-Comté
Guest – Mr. Yves GAILLARD – Lecturer – Université Franche-Comté