頁籤選單縮合
題 名 | 木材塊狀試片剪斷強度之影響因子=Factors Affecting the Shear Strength of Wood Block-shear Specimens |
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作 者 | 蘇文清; 吳孟書; 王怡仁; | 書刊名 | 林產工業 |
卷 期 | 23:4 2004.12[民93.12] |
頁 次 | 頁297-306 |
分類號 | 436.185 |
關鍵詞 | 剪斷強度; 模具偏位; 試片形式; 試片大小; 木破率; Shear strength; Tool offset; Specimen type; Specimen size; Wood failure; |
語 文 | 中文(Chinese) |
中文摘要 | 現行木材剪斷試驗在實木剪斷及膠合剪斷試驗都使用剪斷試塊進行檢測,其試驗方法相似,但是試片形式及模具偏位各有不同。本研究的目的在改變影響木材剪斷試驗的因子,對實木及膠合木材進行剪斷試驗,以瞭解各因子對剪斷強度的影響。試驗因子包含樹種(杉木、柳杉、白櫟木及硬槭)、模具偏位有無(無偏位及2mm偏位)、試片形式(實木單缺口、實木雙缺口及膠合雙缺口)及試片大小(大試片及小試片)四種。剪斷試驗以材料試驗機在每分鐘5mm的位移速度下進行,試片破壞後,計算剪斷強度。剪斷強度數值利用SPSS(Statistical Package for Social Science)套裝軟體分析各因子對剪斷強度的影響。 分析杉木及柳杉的試片大小對於剪斷強度之影響,得到試片大小對剪斷強度是沒有統計上的差異。在實木單缺口、實木雙缺口及膠合雙缺口對剪斷強度之分析,發現三者順序是以實木單缺口之剪斷強度之間無法有明確的結論。不同樹種對剪斷強度影響則是比重大者,剪斷強度大,四種樹種之剪斷強度是以硬槭為最大,柳杉為最小。破壞模式於四種樹種大都沿剪斷面的破壞,但杉木及柳杉另有傾斜的剪斷,而柳杉及白櫟木因早晚材明顯,故剪斷易延伸至早材。 |
英文摘要 | The block-shear specimens have been used in solid wood and adhesively bonded wood to evaluate shear strength. The shear specimens and the test methods are similar, but the specimens type and the offset of shear tool are different. The purpose of this research was to study factors affecting strength of block-shear specimens for solid wood and adhesively bonded wood. Experimental factors including wood species (China fir, Japanese cedar, white oak and hard maple), shear tool with or without offset (without offset and 2-mm offset), specimens types (single-notched solid wood, double-notched solid wood and adhesively bonded block-shear specimens) and specimens sizes (large and small specimen) were studied. The shear tests were carried out by an universal testing machine at rate of 5 mm/min. Shear strength was calculated after specimen failed. The statistical analyses were carried out by SPSS (statistical Package for Social Science). It was found that the specimen sizes effect on shear strength for China fir and Japanese cedar was not significant. According to the analysis of the shear strength for three specimen types, the shear strength of single-notched solid wood was smaller than that of double-notched and adhesively bonded block-shear specimens. No statistically significant difference was found in shear strength between shear tool with and without offset for white oak. In respect of species affecting shear strength, the larger specific gravities of the species, the higher shear strength of the species. The shear strength of hard maple was the highest, and the shear strength of Japanese cedar was the lowest. The shear failure modes for four species of solid wood were mostly along the shear plane. Shear failure occurred with an angle to the assumed shear plane was found for China fir and Japanese cedar. The early wood and later wood is distinct for China fir and white oak, so shear failure always extends to the spring wood. |
本系統中英文摘要資訊取自各篇刊載內容。