The effect of temperature and moisture content on the mechanical behaviour of wood: a comprehensive model applied to drying and bending

• Published in: European journal of mechanics, A, Solids Vol. 26; no. 3; pp. 558 - 572
• Main Authors: Rémond, R., Passard, J., Perré, P.
• Format: Journal Article
• Language: English
• Published: Paris Elsevier Masson SAS 01.05.2007; Elsevier
• Subjects: Applied sciences; Chemical and Process Engineering; Devices using thermal energy; Dryers; Drying stress; Energy; Energy. Thermal use of fuels; Engineering Sciences; Exact sciences and technology; Food engineering; Fundamental areas of phenomenology (including applications); Life Sciences; Mechano-sorption; Modelling; Physics; Polymer industry, paints, wood; Solid mechanics; Static elasticity (thermoelasticity...); Structural and continuum mechanics; Viscoelasticity; Wood; Wood. Paper. Non wovens; Viscoelasticity; Modelling; Drying stress; Wood; Mechano-sorption; Constitutive equation; Hygrothermal variation; Temperature effect; Shrinkage; Modeling; Freezing; Sorption; Thermal activation; Heat mass transfer; Freeze; Drying; DRYING STRESS; MECHANO-SORPTION; MODELLING; WOOD; VISCOELASTICITY
• ISSN: 0997-7538; 1873-7285
• DOI: 10.1016/j.euromechsol.2006.09.008

This paper proposes a model able to simulate heat and mass transfer and mechanical behaviour of a wooden board during processing. The coupled heat and mass transfer equations are solved using an existing computational model named TransPore. From the moisture content and temperature profiles, a rigorous one-dimensional formulation and a relevant constitutive model are used to calculate the stress and strain evolution within the board due to shrinkage or external loading. This allows a fast, comprehensive and realistic model to be implemented. Used as a tool, it allowed us to gain new insights into industrial operations: – the post-drying storage stage instead of the drying operation by itself is responsible for the high risk of checking encountered when drying thick boards; – the hydro-thermal activation is of utmost importance in wood bending and subsequent shape freezing.