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| PDF : |  08040170.pdf |
| title(En) : | The Effects of Temperature on Compressive Properties Perpendicular to Grain of Wood. |
| author(En) : | Manjiro Fukuyama, Tomio Takemura |
| information : | Mokuzai Gakkaishi 8(4), 170-176 (1962) |
| assort : | Original Article |
| summary(En) : | The effects of temperature on the static strength and the modulus of elasticity perpendicular to grain must be considered in the various problems of wood-working processes, especially those of plywood, improved wood and kiln drying. This paper deals with the effects on the compressive strength σp: stress at proportional limit, σ2.5: stress at 2.5% strain, σ5.0: stress at 5.0% train) and modulus of elasticity in compression (E) in tangential direction. The test pieces (cross section: 2×2 cm2, length: 4 cm) of Hinoki (Chamaecyparis obtusa) and Buna (Fagus crenata) were used. The investigations were conducted at temperatures of 30, 45, 60 and 75°C under the nominal moisture contents of 7, 13, 18, 24% and green. The results obtained are as follows: 1) The stress-strain curves were approximately linear in a range of small strain, and the range grows narrower with the increases of temperature and moisture content (Fig. 1). 2) The values of σp, σ2.5, σ5.0 and E decrease almost linearly with the increase of temperature (Fig. 2∼5) and the temperature coefficients show maxima at a moisture content of 18∼20% (Table 3). 3) The percentage changes in σp, σ2.5, σ5.0 and E with change in the moisture content increase with the temperature rise (Fig. 6 and Table 4). 4) The relations of σp, σ2.5, σ5.0 and E to the temperature and the moisture content in the range investigated are represented by the equation (3) and the parameters are given in Table 5. |