頁籤選單縮合
題 名 | 杉木建材之破壞性與非破壞性強度 |
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作 者 | 周群; | 書刊名 | 林產工業 |
卷 期 | 9:4 1990.12[民79.12] |
頁 次 | 頁39-50 |
分類號 | 436.187 |
關鍵詞 | 杉木; 非破壞性; 建材; 破壞性; 強度; |
語 文 | 中文(Chinese) |
中文摘要 | 木材具天然之缺點甚多,影響其強度極大,故欲由小試片之靜曲強度來推測實木樑之抗彎強度會產生很大誤差。近來由於FFT頻譜分析儀的推出,使非破壞性振動試驗直接用於材質的分析上,變為實際可行。本研究目的即在以振動試驗計算出之動彈性係數推翻疏伐小徑杉木之靜曲強度,並探討小試片與實木樑各項彎曲特性之相關性。研究結果發現,杉木之年平均胸徑生長量約為1.1cm;疏伐小徑杉木實木樑之破壞係數為小試片之69.1%(413.4/598.2),而小試片之抗彎強度則為成熟材小試片之68.6%(598.2/872);實木樑中彎曲與軸向動彈性係數其最佳之相關性(決定係數R^2=0.891),且由軸向動彈性係數預測靜曲彈性係數,其決定係數可高達0.427,但與破壞係數之相關性,R^2則只達0.163;小試片之各項彎曲特性之相關性,均較受缺點影響之實木樑者為佳;至於實木樑典小試片間各項動彈性係數間相關性良好。 |
英文摘要 | The strength of wood materials, as a natural resource, is affected by its natural defects. The estimation of the bending strength of solid beam from clear small specimen tests is, therefore, strongly biased. The use of non-destructive test on solid beams to estimate their bending strength is more reliable and possible due to the development of FFT spectrum analyzer. The objective of this study is to estimate the static bending strength of solid beams by dynamic moduli of elasticity obtained from vibrational tests. The relationship of bending properties between clear small specimen and solid beam is also investigated. Test results show that the average diameter growth is about 1.1 cm. The bending strength of small-diameter solid beam from thinning was only 69.1% (413.4 / 598.2) of that of small clear specimen. The bending strength of clear small specimen from small-diameter log was only 68.6% (598.2/872) of that of mature wood. The best relationship (R^2=0.891) was found between bending dynamic MOE and axial dynamic MOE. The static bending MOE of solid beam was strongly related with that ofaxial dynamic MOE (R^2=0.427). However, the relationship between the modulus of rupture and axial dynamic MOE was low (R^2=0.163) for solid beam. The relationships between bending properties of clear small specimen were better than those of solid beam. The dynamic MOE of solid beam could be predicted successfully by the dynamic MOE of clear small specImen. |
本系統中英文摘要資訊取自各篇刊載內容。