Agritrop
Home

Application of ultrasonic tomography to characterize the mechanical state of standing trees (Picea abies)

Brancheriau Loïc, Ghodrati A., Gallet Philippe, Thaunay Patrice, Lasaygues Philippe. 2012. Application of ultrasonic tomography to characterize the mechanical state of standing trees (Picea abies). Journal of Physics. Conference Series, 353 (012007), 14 p. Anglo-French Physical Acoustics Conference. 10, Fréjus, France, 19 January 2011/21 January 2011.

Journal article ; Article de revue à comité de lecture
[img] Published version - Anglais
Access restricted to CIRAD agents
Use under authorization by the author or CIRAD.
document_563619.pdf

Télécharger (1MB)

Abstract : Wood is a biological growth medium. It is orthotropic with longitudinal, radial and tangential axes. Furthermore, standing trees adapt themselves to environmental growth conditions, and their material properties vary with age. These changes result in variations that are much more complex than anisotropy. Studying wood quality and intraspecific variability is useful for clonal selection and for the genetic improvement of plantations. In this study, two logs of Picea abies underwent transmission tomography. The mean diameter was 16 cm (26-year-old tree) and the moisture content was 22%. The effect of the presence of bark and artificial defects was investigated. The tomographic device was specifically built for tree imaging. The imaging process was automatic with 900 ultrasonic acquisitions in 40 minutes (emission at 55 kHz with 5 periods of square wave form). The main conclusions were: speed near the bark is higher than in the centre because of the existence of juvenile wood combined with the moisture content gradient (moisture content lower near the bark). Likewise, damping near the bark is lower than in the centre. A significant relationship was observed between slowness and attenuation (R²=0.50); when the speed increased, damping decreased. No clear effect of the presence of bark was shown on the tomographic images. The bark was thin (3 to 5 mm thick) compared to the wavelength (26 mm). The 10, 20 and 50 mm artificial holes were clearly visible on the tomographic images. However, quantitative tomography does not enable the precise location of defects. (Résumé d'auteur)

Mots-clés Agrovoc : Picea abies, Bois, Ultrason, Propriété mécanique, Propriété physicochimique

Mots-clés géographiques Agrovoc : Iran République islamique

Classification Agris : U30 - Research methods
K50 - Processing of forest products
F50 - Plant structure

Champ stratégique Cirad : Axe 1 (2005-2013) - Intensification écologique

Auteurs et affiliations

  • Brancheriau Loïc, CIRAD-PERSYST-UPR Bois tropicaux (FRA) ORCID: 0000-0002-9580-7696
  • Ghodrati A., Islamic Azad University (IRN)
  • Gallet Philippe, CIRAD-PERSYST-UPR Bois tropicaux (FRA)
  • Thaunay Patrice, CIRAD-PERSYST-UMR Qualisud (FRA)
  • Lasaygues Philippe, CNRS (FRA)

Autres liens de la publication

Source : Cirad - Agritrop (https://agritrop.cirad.fr/563619/)

View Item (staff only) View Item (staff only)

[ Page générée et mise en cache le 2021-03-26 ]