ISSN:
1611-4663
Keywords:
Hot-pressed wood
;
Creep
;
Cyclic moisture sorption
;
Bending stress
;
Sugi
Source:
Springer Online Journal Archives 1860-2000
Topics:
Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
,
Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
Notes:
Abstract This study examined the bending creep behavior of hot-pressed wood during cyclic moisture changes. Sugi (Cryptomerica japonica D. Don) specimens were pressed in the radial direction under six combinations of nominal compressive strain (33% and 50%) and press temperatures (140°C, 170°C, 200°C). Creep tests were conducted at 20°C with three cyclic relative humidity changes between 65% and 95% under 25% of short-breaking stress. The effect of moisture content (MC) change on elastic compliance and mechanosorptive (MS) compliance was investigated. The relation between MS compliance and thickness swelling was studied. The results indicated that total compliance increased over the history of cyclic moisture changes; and its behavior was closely related to the changes in MC and thickness swelling. The total compliance increased during adsorption and decreased during desorption. Elastic compliance increased linearly with MC and was dependent on press temperature and compression. With increasing MC change, MS compliance increased during adsorption and decreased during desorption. The first adsorption led to greater MS compliance than did the subsequent adsorption with the same amount of MC change. In general, the elastic parameterK E and the MS parameterK Mincreased with compression and decreased as the press temperature increased. The MS parameterK M was apparently greater than the elastic parameterK E. The MS parameterK M increased with swelling coefficient KSW of the hot-pressed specimen during adsorption and decreased with an increasing shrinkage coefficientK SH during desorption.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF00765799
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