應力波檢測技術應用於樟木圓盤內部孔洞之評估

The Application of Stress-wave Method to Evaluate the Internal Hole of Camphor Wood (Cinnamomum camphora) Disks

陳建銘(Chien-Ming Chen) ； 李佳如(Chia-Ju Lee) ； 楊德新(Te-Hsin Yang)

《林產工業》 32卷3期 (2013/09) Pp. 129-137

https://doi.org/10.6561/FPI.2013.32(3).1

摘要

本研究選用台灣古蹟木結構中常見之樟木，應用人工開孔方式，製造孔洞模擬木結構構件之內部損害狀態，並應用應力波檢測技術進行評估，探討不同含水率下與不同內部孔洞之應力波傳遞速度變化以及減低率和孔洞面積比值之關係。結果指出，受測試材由高含水率減低至低含水率時，其橫向應力波傳遞速度變化並不顯著，顯示橫向應力波傳遞速度不受試材含水率變化之影響。透過人工模擬不同孔洞大小與應力波傳遞路徑的結果得知，四種傳遞路徑中，以135度弦徑向和徑向之應力波傳遞速度與中央孔洞面積率有顯著的負相關性，而相對應力波傳遞速度減低率與孔洞面積率則有顯著的正相關性，另利用弦向和徑向之應力波傳遞速度比值（V_(90)/V_(180)）可有效評估孔洞發生位置及其大小，可作為未來評估樟木內部缺陷之參考。

關鍵字

樟木 ； 非破壞性評估 ； 應力波檢測技術

並列摘要

The main objectives of this study are to evaluate the internal defect of camphor wood disks by using stress-wave method, the effects of moisture content on the transversal stress-wave velocity of camphor wood and the relationships among the size and location of internal defect and stress-wave velocity are also investigated. The experimental results revealed that the effects of moisture content on the transversal stress-wave velocity (Path A, B, C and D) of wood were not significant. Among the pathways of transversal stress-wave velocities, the significant negative relationships were found between hole area ratio (HA) and transversal stress-wave velocities in Path C and Path D. Results also indicated that the ratio of stress-wave velocity along Path B and Path D (V_(90)/V_(180)) increased with increasing HA, in addition, the size and location of the internal defect in camphor wood could be detected effectively by using the ratio of V_(90)/V_(180). The stress-wave method could be applied to evaluate the internal defects of camphor wood structural timber.

並列關鍵字

Camphor wood (Cinnamomum camphora) ； Nondestructive evaluation ； Stress wave technique