On the time-temperature equivalency in green wood: Characterisation of viscoelastic properties in longitudinal direction

Jana Dlouha (1) , Bruno Clair (1) , Olivier Arnould (1) , Petr Horacek (2) , Joseph Gril (1)

1 MAB - Mécanique de l'Arbre et du Bois
2 MENDELU - Mendel University in Brno

Aiming at modelling tree mechanics, viscoelastic properties of green wood along fibres was investigated through a sequence of creep tests in the temperature range of 308C-708C. The apparent validity of time-temperature equivalency was questioned by discrepancies evidenced in the approximated complex plane (ACP). This paradox was solved by assuming that the temperature not only accelerates the viscoelastic processes but also slightly increases their intensity. This softening effect of the temperature on the compliance was described by a 2nd degree polynomial. Time-temperature dependency fitted very well to the Arrhenius law up to 608C. Based on the ACP, the power law was proposed for modelling creep behaviour in green wood. The method was successfully used for all specimens investigated.

Mots clés: green wood; time-temperature equivalency; viscoelastic properties

Domaines: Autre

Jana Dlouha, Bruno Clair, Olivier Arnould, Petr Horacek, Joseph Gril. On the time-temperature equivalency in green wood: Characterisation of viscoelastic properties in longitudinal direction: Characterisation of viscoelastic properties in longitudinal direction. Holzforschung, 2009, 63 (3), pp.327-333. ⟨10.1515/HF.2009.059⟩. ⟨hal-00437887⟩