1994 Fiscal Year Final Research Report Summary
Thermal behavior at wood and composite wood surfaces
| Project/Area Number |
05452321
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| Research Category |
Grant-in-Aid for General Scientific Research (B)
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| Allocation Type | Single-year Grants |
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| Research Field |
林産学
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| Research Institution | KYOTO UNIVERSITY |
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Principal Investigator |
SADOH Takeshi Kyoto Univ., Faculty of Agr., Professor, 農学部, 教授 (00026494)
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| Co-Investigator(Kenkyū-buntansha) |
NAKAMURA Masashi Kyoto Univ., Faculty of Agr., Instructure, 農学部, 助手 (10227936)
MASUDA Minoru Kyoto Univ., Faculty of Agr., Associate Professor, 農学部, 助教授 (40027165)
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| Project Period (FY) |
1993 – 1994
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| Keywords | Wood / Wood composite / Surface / Thermal behavior / Fiber orientation / Density / Knot / Defect |
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| Research Abstract |
The end surfaces absorbed 1.2 times more heat than did these of edge-grained surfaces when the surfaces are irradiated with incandescent lamps. The rate of surface temperature rise for various wood and composite wood with various colors and densities was determined when they were irradiated with incandescent lamps.
Thermal behavior at a boundary between human skin and wood composites was simulated. The thermal transfer model based on numerical method with finite differences was proposed to analyze the changes in temperature and rate of heat transfer at the interfeaces. The model was valuable to estimate the sensory warmth felt by man's palm in conact with the wood surface.
The thermogaphic method was applied to detect the knots, using with a difference in thermal properties of knot from the surrounding tissues for softwood species. The lumber surface was radiated with incandescent lamps and the rate of change in surface temperature was measured. As the results the rate of temprature rise was the lowest on the knot, follwed by distored grain region. From the thermograph at 60s after commencement of heating it has been found that the knot sizes could be detected.
Heat is generated according to the energy loss of hysteresis loops which is obs erved at stress-strain curves of defect portions. Cracks and some kinds of defects could be detected by chermal images with repeated bending.
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