Éditeur(s) : HAL CCSD Elsevier
Résumé : International audience
This paper presents Digital Image Correlation (DIC) and Infrared Thermography (IRT) methods to investigate the thermomechanical behavior of an aluminum at the microstructural scale. Electron BackScattered Diffraction (EBSD) is used to characterize the microstructure of a 3 mm thick specimen with centimetric grain size. This study combines the following imaging techniques: DIC to obtain displacement and strain fields during the test, and IRT to estimate temperature and heat source fields induced by the mechanical loading. Ultimately, the aim of this methodology is to provide energy balance during mechanical test at the scale of the microstructure, in order to propose thermomechanical con-stitutive modelling of crystalline plasticity.
ISSN: 0143-8166

hal-01287711
https://hal.archives-ouvertes.fr/hal-01287711
https://hal.archives-ouvertes.fr/hal-01287711/document
https://hal.archives-ouvertes.fr/hal-01287711/file/Local_experimental_investigations_Li_al_2016.pdf
DOI : 10.1016/j.optlaseng.2016.01.001

Éditeur(s) : HAL CCSD Springer Verlag (Germany)
Résumé : International audience
*Context Increased knowledge on diversity in wood properties would have implications both for fundamental research and for promoting a diversification of uses as material. *Aims The objective is to contribute to overcoming the critical lack of data on the diversity of wood dynamic mechanical/viscoelastic vibrational properties, by testing lesser-known species and categorizing sources of variability. *Methods Air-dry axial specific dynamic modulus of elasticity (E'/γ) and damping coefficient (tanδ) were measured on a wide sampling (1792 specimens) of 98 wood types from 79 species. An experimental device and protocol was designed for conducting systematic (i.e. rapid and reproducible) characterizations. *Results Diversity at the specimens' level corroborates the "standard" relationship between tanδ and E'/γ, which is discussed in terms of orientation of wood elements and of chemical composition. Diversity at the species level is expressed on the basis of results for normal heartwood, with specific gravity (γ) ranging from 0.2 to 1.3. Axial E'/γ ranges from 9 to 32 GPa and tanδ from 4×10-3 to 19×10-3. Properties distribution follows a continuum, but with group characteristics. The lowest values of tanδ are only found in certain tropical hardwoods. Results can also suggest alternative species for musical instruments making.
Annals of Forest Science

hal-00808242
https://hal.archives-ouvertes.fr/hal-00808242
https://hal.archives-ouvertes.fr/hal-00808242/document
DOI : 10.1007/s13595-011-0166-z