台灣櫸、長尾尖櫧及光臘樹樹幹內木材強度變異性

Within Trunk Variability of the Strength Property of Wood from Zelkva, Caudate Leaved Chinkapin and Formosan Ash

唐讓雷(Jung-Lei Tang)

《林產工業》 9卷1期 (1990/03) Pp. 29-41

摘要

本研究探討台灣櫸、長尾尖櫧及光臘樹材之直幹材內木材強度性質隨樹高與方向之變異性。藉由不同強度性質之測試與結果分析可知，台灣櫸材之靜曲抗彎及縱向壓縮強度隨樹高增加而增強，但是剪力強度却有顯著之相反結果出現。長尾尖櫧與光臘樹材均顯示靜曲抗彎及縱向壓縮強度隨樹高方向而降低，而剪力強度呈隨樹高而降低後再增高之現象。對不同取材方向之比較，各不同強度在各方向間變異顯著性不一，三樹種間站台灣櫸材對方向性之變異最小，其次為長尾尖櫧，而光臘樹變異最大。樹種不同，其不同木材強度性質亦顯示不同程度變異，台灣櫸材以剪力及縱向壓縮強度之變異較大，長尾尖櫧以靜曲強度變異居高，而光臘樹又以靜曲強度與縱向壓縮為較高者。

關鍵字

木材強度 ； 木材性質變異 ； 直幹內變異性 ； 台灣櫸 ； 長尾尖櫧 ； 光臘樹 ； 省產材 ； 重要經濟樹材

並列摘要

The wood of zelkova, caudate leaved chinkapin, and formosan ash at different height and directional (on cross section) positions within the tree trunks was taken for the strength property tests. It was found that the wood of zelkova showed an increase in the bending and longitudinal compression strengthes with increasing the height position, whereas the significant reverse result was observed for the shear strength property. Both the wood of caudate leaved chinkapin and formosan ash showed an decrease in the bending and longitudinal compression strengthes with increasing the height position. The shear strength decreased with the height position as mentioned above but it showed an increase at a higher position of tree trunk. Among the three wood species, zelkova had the least directional variation, caudate leaved chinkapin in between and formosan ash the largest.

並列關鍵字

Wood strength ； property variation of wood ； variation within trunk ； zelkova ； caudate leaved chinkapin ； formosan ash ； domestic wood of Taiwan ； irnportant economical wood