Abstract
Changes in the modulus of elasticity (MOE), modulus of rupture (MOR), and stress relaxation in the radial direction of wood (hinoki:Chamaecyparis obtusa) moisture-conditioned by the adsorption process from a dry state and by the desorption process from a moisture content slightly below the fiber saturation point were investigated. The MOE and MOR of wood conditioned by the adsorption process showed significant increases during the later stages of conditioning when the moisture content scarcely changed. However, with the desorption process they did not increase as much during later stages of conditioning, though they increased during early stages of conditioning when the moisture content greatly decreased. The stress relaxation of wood decreased with an increase in the conditioning period with both the adsorption and desorption processes. These results suggest that wood in an unstable state, caused by the existing state of moisture differed from that in a true equilibrium state shows lower elasticity and strength and higher fluidity than wood in a true equilibrium state. Furthermore, the present study demonstrates that the unstable states of wood induced during the course of drying, desorption, and possibly adsorption of moisture are slowly modified as wood approaches a true equilibrium state.
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Furuta Y, Norimoto M, Yano H (1998) Thermal-softening properties of water-swollen wood. V. The effect of drying and heating histories (in Japanese). Mokuzai Gakkaishi 44:82–88
Ishimaru Y, Narimoto S, Iida I (2001) Mechanical properties of wood swollen in organic liquids with two or more functional groupes for hydrogen bonding in a molecule. J Wood Sci 47:171–177
Ishimaru Y, Arai K, Mizutani M, Oshima K, Iida I (2001) Physical and mechanical properties of wood after moisture conditioning. J Wood Sci 47:185–191
Furuta Y, Yano H, Kajita H (1995) Thermal-softening properties of water-swollen wood. I. The effect of drying history (in Japanese). Mokuzai Gakkaishi 41:718–721
Miyabe H (ed) (1968) In: Japan Society of Polymer Science: hand book of material and moisture [Zairyo to Mizu Handbook] (inJapanese). Kyoritu Shuppan. Tokyo, pp 240–262
Ishimaru Y., Minase T (1992) Mechanical properties of wood in various stages of swelling. I. Mechanical and swelling behavior of wood swollen in various organic liquids (in Japanese). Mokuzai Gakkaishi 38:550–555
Tokumoto M (1994) Creep and set of wood in the non-equilibrium states of moisture (in Japanese). Mokuzai Gakkaishi 40:1157–1164
Suzuki M, Nakato K, Aikawa K (1965) Frequency dependence of dynamic Young's modulus of wood and its relation to creep (in Japanese). Mokuzai Gakkaishi 11:76–82
Onogi S (1973) Principles of rheology (in Japanese), 3rd edn. Maki Shoten, Tokyo, pp 97–102
Grossman PUA (1976) Requirement for a model that exhibits mechano-sorptive behavior. Wood Sci Technol 10:163–168
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Ishimaru, Y., Oshima, K. & Iida, I. Changes in the mechanical properties of wood during a period of moisture conditioning. J Wood Sci 47, 254–261 (2001). https://doi.org/10.1007/BF00766710
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DOI: https://doi.org/10.1007/BF00766710