微破壞儀評估台灣杉造林木之壓縮強度

Assessment of the Crushing Strength of Plantation Taiwania by Using the Fractometer

林振榮(Cheng-Jung Lin) ； 王松永(Song-Yung Wang) ； 邱志明(Chih-Ming Chiu)

《林產工業》 23卷1期 (2004/03) Pp. 23-31

https://doi.org/10.6561/FPI.2004.23(1).3

摘要

本研究目的在利用微破壞儀檢測取樣自台灣杉樹蕊試材的壓縮強度，台灣杉胸徑32.4-44.4 cm（type A）、25.2-30.0 cm（type B）、18.0-22.8 cm（type C）之縱向或弦向壓縮強度，結果為Type C＞Type B ＞Type A，統計分析得知Type C有較大的壓縮強度值。縱向壓縮強度在樹幹橫向之變異性，Type B及Type A橫向變異為從髓心開始最低逐漸上升至約10-12 cm處之後不規則變化。Type C在橫向變其為從髓心開始緩慢下降至3 cm後保持一定波動變化至5 cm處後再上升至樹皮側。壓縮強度隨著樹木胸高徑的增加而下降，兩者相關性極顯著。從縱向壓縮強度的變化趨勢得知，成熟材及未成熟材的境界位於距髓心距離10-15 cm間，約為18-23年生。

關鍵字

縱向壓縮強度 ； 弦向壓縮強度 ； 台灣杉

並列摘要

The main objective of this study is to investigate the crushing strength of plantation Taiwania (Taiwania cryptomerioides Hay) by using the Fractometer. The samples can be classified into three types on the basis of diameter at breast height (DBH) namely: 32.4-44.4 cm (type A), 25.2-30.0 cm (type B), and 18.0-22.8 cm (type C). The results showed that the order of the average crushing strength ( compression in longitudinal and tangential direction) of plantatoin Taiwania are Type C ＞ Type B ＞ Type A. The type C is the best one when considered in terms of crushing strength. The transversal variations of the compression in longitudinal direction increased from pith outwardly to 10-12 cm and then irregular toward the bark for type A and B, while in the case of type C, which decreases from pith outwardly to 5-7 cm and then increases. There are very negative significant relationship between the crushing strength and DBH. The juvenile wood region was around 10-15 cm away from the pith by segmented regression analysis for crushing strength parallel to the grain, and the age of Taiwania was about 18-23 years aids.

並列關鍵字

Fractorneter ； compression strength in longitudinal direction ； compression strength in tangential direction ； Taiwania