Evidence and modelling of physical aging in green wood

Jana Dlouha (1) , Joseph Gril (1) , Bruno Clair (1) , Tancrède Alméras (1)

1 MAB - Mécanique de l'Arbre et du Bois

Physical aging typical of semi-crystalline polymers was evidenced in green (never dried) wood from three tropical hardwood species. The assumption of uniform aging rate was verified by the construction of master curves from series of tensile creep tests in the fibre direction, performed at increasing time elapsed after a quench following heating above the glassy transition. The rheological response during periods of creep small enough to neglect the progress of aging was described by a model made of a spring in series with a parabolic dash-pot where only the characteristic time depends on the aging time. The model was able to describe results obtained by a previous author on softwood loaded transversally to the fibres. The possible role of a transient adsorption process consecutive to the quench is discussed.

Mots clés: Physical aging; Creep; Green wood

Domaines: Autre

Jana Dlouha, Joseph Gril, Bruno Clair, Tancrède Alméras. Evidence and modelling of physical aging in green wood. Rheologica Acta, 2009, 48 (3), pp.333-342. ⟨10.1007/s00397-008-0325-9⟩. ⟨hal-00437882⟩