Please use this identifier to cite or link to this item: http://hdl.handle.net/11455/65666
標題: 應力波非破壞測定法檢測家具構件接合強度
Determination of Joint strength of Furniture Components by Nondestructive Testing Method with Stress Wave
作者: 陳合進
Chen, Ho-chin
關鍵字: Stress Wave;應力波;Nondestructive;Withdrawal load;maximal bending monent;非破壞;引拔載重;最大彎矩
出版社: 森林學系
摘要: 
本研究主要在分析 3 種應力波非破壞性測定法,用於檢測巴杜柳桉和紅
櫟木兩種闊葉樹材及花旗松和美國西部鐵杉兩種針葉樹材,製作的 4 種
縱向接合法及 3 種 T 型接合法構件之接合強度,及預測構件缺點之可行
性,並比較其與傳統破壞性檢測接合強度之相關性。在縱向接合方面,試
材經接合後波速會明顯增快,而振動頻率則沒有一定趨勢。在靜曲破壞強
度試驗時,樹種中以巴杜柳桉最大,花旗松最小;接合法則以指接的強度
最大對接最小;靜曲彈性係數試驗時,樹種以巴杜柳桉最大花旗松最小;
接合法之間沒有一定的趨勢。至於 MOEd 與 MOE 之相關性,經簡單直線
迴歸分析結果, 4 樹種中以花旗松的相關性最高,其 r2 值在0.85以上
,而美國西部鐵杉的相關性最低,r2 值在0.50 以下。T 型構件檢測方面
,因振動頻率測定器出現較不穩定的狀況,只能應用應力波計時儀和打音
頻譜分析系統加以檢測;試材加工前後之波速並沒有明顯的差異,但構件
組合後橫檔之波速會變慢;未佈膠引拔構件的波速比雙面佈膠引拔構件的
波速慢。以打音頻譜分析系統檢測構件縱向振動頻率時,抗彎構件中兩針
葉樹材之振動頻率比兩種闊葉樹材低;振動頻率會隨著榫頭長度之增長而
增高,未佈膠引拔構件之振動頻率(3401 Hz)比雙面佈膠構件(3824 Hz)
低。4 種樹種的構件引拔載重以紅櫟木最大,花旗松最小;3 種接合法之
引拔載重以橢圓榫最大,方榫次之,木釘接合最小;構件的引拔載重會隨
著構件榫頭長度增長而提高;所有構件中以榫長 40 mm 的強度最大(2003
kgf),而未佈膠構件之強度最低(137 kgf);榫頭寬度 +0.5 mm 嵌合度的
構件強度會明顯的降低。構件最大彎矩方面以紅櫟木最大,巴杜柳桉次之
, 2 種針葉樹材差異不顯著;3 種接合法中以方榫之最大彎矩最大,橢
圓榫次之,而木釘接合最低;榫頭厚度 +0.5 mm嵌合度之構件,其最大彎
矩比嵌合度±0 的構件大;3 種膠合劑對最大彎矩之影響有顯著的差異。
構件經非破壞性測定之波速、振動頻率與破壞性測定之引拔載重或最大彎
矩間,經簡單直線迴歸分析結果,相關性並不高;另外於不同接合型態之
構件其引拔載重與振動頻率的迴歸分析中 r2 值為 0.80,由此結果可知
,利用打音頻譜分析系統可檢測出橢圓榫不同接合型態構件之間的差異。

The stress-wave nondestructive test (NDT) method was applied in
this research to test the joint strength for four kinds of
longitudinal joint and three kinds of T-type joint of Selangan
batu, Red oak, Douglas fir and American hemlock, and try to
predict the joint defect. The relationship of joint strength
predicted by NDT and tested traditional destructive method was
correlated.For the longitudinal joint , the wave velocity of all
samples would become obviously faster after jointed, but no
constant tendency in vibration frequency was observed. Bending
test showed that the MOR among the wood species, Selangan batu
had higher strength value, and Douglas fir was the lowest.
Among the joint methods, the best one was finer-joint, and the
worst one was butt joint. MOE of tested wood species, showed
same tendency as MOR showed, but the variation of joint was not
significant. The relationship between MOEd and MOE was tested by
linear regression analysis, the Coefficients of correlation
determination showed that the highest value was Douglas fir
(r2>0.85), and the lowest for American hemlock (r2<0.50).For
the T-type component side, only the stress-wave timer and tap
tone analysis system were applied. The vibration frequency
tester showed unstable result, therefore this method was
excluded in this study. The wave velocity did not have
significant difference before and after the T-type component was
assembled, but it showed slower velocity after the components
were assembled. While the longitudinal frequency was measured by
tap tone analysis system, it was found that the value of
softwood was lower than that of hardwood. The vibration
frequency was positively correlated with tenon length, and the
value of withdrawal component of non-spread glue (3401 Hz) was
lower than the double-spread one (3824 Hz). The withdrawal
strength showed that the best was Red oak, and the worst was
Douglas fir. For joint methods, it showed that the best was
oval-end mortise and tenon joint, followed by square-end mortise
and tenon joint, and dowel joint. The withdrawal strength was
positively correlated with tenon length. Among the all
components, the highest withdrawal strength was 2003 kgf for 40
mm tenon length , and the lowest was 137 kgf for the case
without glue. The withdrawal strength of tenon width with +0.5
mm fitness would be obviously decreased.For the bending moment
of the T-type components, the best was Red oak, and the second
was Selangan batu with a little difference. Among the joint
methods, the best was square-end mortise and tenon joint, the
second was oval-end mortise and tenon joint, and the worst was
dowel joint. The bending moment of the tenon thickness with +0.5
mm fitness was better than 0 one, and there was significant
variation among three kinds of glues used in this study. The
correlation of withdrawal strength and bending moment measured
by destructive test and predicted by NDT was not significant
tested by linear regression analysis. The different joint type
which r2 value of regression analysis by withdrawal strength and
vibration frequency was 0.80. It could be concluded that the tap
tone frequency analysis system could be applied in prediction
the variation of different joint components of oval-end mortise
and tenon joint.
URI: http://hdl.handle.net/11455/65666
Appears in Collections:森林學系

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