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No.37 (1990/12) >

 
Title :小型木材試験片の膨潤乾縮量測定(林学科)
Title alternative :Measurements of swelling and shrinkage with small wood specimen (Department of Forestry)
Authors :林, 弘也
Authors alternative :Hayashi, Hiroya
Issue Date :5-Dec-1990
Abstract :小型木材試験片の膨潤乾縮量をストレインゲージで計測し,測定の条件を検討した。試験片の調湿にかなりの時間を要するが,ストレインゲージによる測定は自動的に実施することが可能であり,かつ調湿した雰囲気の中で計測できるので比較的精度よく,かつ容易であった。単一の履歴を持つ広葉樹散孔材の試験材で膨潤乾縮量を測定した。相対湿度18-100%の範囲で膨潤乾縮を1-4回繰り返した。実験結果では,材の乾縮量は飽湿状態を経験しても変動が大きく一定の傾向はないが,膨潤量は減少する。材を熱処理すると,乾縮量と膨潤量とも増大し,これは材の内部的な応力の解除によると推測された。
A method used wire strain gage for dimensional change in swelling and shrinkage of small wood specimen and measuring conditions are described. Conditioning time of wood specimen in some relative humidity is needed relatively long time. It is about 10 hours in this experiment. As it is measured mechanically relative humidity in the desiccator and dimensional change of the specimen remained in the conditioning desiccator by the personal computor, measurement is done precisely and readily in this method. It is measured dimensional change in swelling and shrinkage of diffuse porous woods with same history. Wood specimens are conditioned in the atomosphere from 18% R. H. to nearly 100% R. H. at 25℃. A dimensional change is measured 1-4 cycle per one specimen in above mentioned condition. Moisture at fiber saturation point does not effect dimensional change in shrinkage but decrease dimensional change in swelling. Dimensional change in swelling and shrinkage is increased by heat treatment. It is supposed that this increasing comes from cancellation of internal stresses in wood.
Type Local :紀要論文
ISSN :0370-4246
Publisher :琉球大学農学部
URI :http://hdl.handle.net/20.500.12000/3865
Citation :琉球大学農学部学術報告 = The Science Bulletin of the Faculty of Agriculture. University of the Ryukyus no.37 p.225 -230
Appears in Collections:No.37 (1990/12)

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