Caractérisation Multi-échelle de L'amortissement Des Matériaux Composites À Fibres Végétales

Download or read book Caractérisation Multi-échelle de L'amortissement Des Matériaux Composites À Fibres Végétales written by Taiqu Liu and published by . This book was released on 2021 with total page 2021 pages. Available in PDF, EPUB and Kindle. Book excerpt: Vibration and noise are unavoidable problems in engineering products and daily life. Thus, the knowledge of the damping performances of engineering materials and the factors that affect these properties are highly required. Plant fiber composites (PFCs) have become a new option when considering the compromise between damping and stiffness. Current researches on damping are mainly work at the macroscale and the damping sources and mechanisms in plant fiber composites are complex and not fully revealed. Thus, the main objective of this thesis is to provide a better characterization and understanding of damping in 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.