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題 名 | 木釘引拔強度的簡易量測法=A Simplified Method for Evaluation of Dowel Joint Withdrawal Strength |
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作 者 | 李世豪; 蔡坤峻; 王怡仁; | 書刊名 | 林產工業 |
卷 期 | 30:2 2011.06[民100.06] |
頁 次 | 頁117-122 |
分類號 | 474.1 |
關鍵詞 | 推出負載; 引拔強度; 木釘接合; Push load; Withdrawal strength; Dowel joint; |
語 文 | 中文(Chinese) |
中文摘要 | 家具是人類生活不可欠缺的器具,對於家具的要求不僅要考慮式樣風格與功能,更要考慮其結構強度與安全。一般家具破壞大都發生在接合處,所以家具結構安全取決於接合強度。木釘常作為家具構件間之接合。木釘接合引拔強度的試驗,一般都使用T型試片。由於木材為直交異方性,圓形斷面的木釘和釘孔會因吸脫濕變形而成為楕圓形斷面,兩個楕圓形的不同配合會造成不同的局部干涉,進而影響木釘接合強度。T型試片的製作是將木釘包埋在釘孔內,因此無法清楚了解兩楕圓形間的干涉配合。為探究此干涉配合現象,本研究直接將木釘裝配在木材試片量測其推出負載。研究目的在檢驗由此簡易方法獲得的木釘接合強度是否與T型試片的引拔強度相同的假設。本試驗使用硬槭為材料,在測試構件鑽兩個直徑為12mm之木釘孔,其中一個木釘孔配合荷重構件與木釘製作成T型試片,另一木釘孔則配合硬槭木釘製成簡化木釘接合,接合使用環氧膠或乳膠,木釘引拔強度和木釘推出負載則使用材料試驗機以2mm.min^(-1)的位移速度量測。配對t檢定發現在5%顯著水準下無法拒絕簡化木釘接合的“推出負載”與T型試片的“引拔強度”相等的假設,亦即推出負載與引拔強度沒有顯著的不同。 |
英文摘要 | Furniture is necessary for human life. The requests for furniture are not only appearance and function but also the strength and safety of structure. The structural safety depends on joint strength because most of furniture's failures occur in joints. Dowel is frequently used to connect members in the panel and frame furniture. T-type dowel joint is always used to test dowel's withdrawal strength in all studies. However, owing to orthogonal and hygroscopic properties of wood, the shape of dowel and dowel hole change from circle to oval during the process of adsorption and desorption. The interference fit caused by these two shape changes could affect the strength of the dowel joint. The conventional T-type dowel joint is made by burying dowel into load and test blocks. Therefore, it is impossible to observe and investigate the interference fit caused by the two oval shapes of dowel and dowel hole. In order to comprehend this phenomenon, dowel was simply glued with the load block. Push load of the simplified wood dowel joint was measured. The objective of this study is to test the hypothesis that the push load of the joint measured by this simplified method is the same as the withdrawal strength measured by the conventional T-type dowel joint. Hard maple was conditioned and machined as test block with two dowel holes with diameter of 12 mm. One dowel hole was fitted with a dowel and a load block both were made of hard maple to form a T-type dowel joint and the other dowel hole was fitted a dowel to form a simplified dowel joint. Epoxy and polyvinyl acetate were used for the joints. The withdrawal strength of the T-type dowel joint and the push load of the simplified dowel joint were tested with a universal testing machine with a speed of 2 mm.min^(-1). The paired t-test at 5% significant level revealed that the hypothesis of the push load of the novel simplified dowel joint equals to the withdrawal strength of conventional T-type dowel joint could not be rejected. |
本系統中英文摘要資訊取自各篇刊載內容。