市售合板剪斷特性之評估

Evaluation on the Shearing Properties of Commercial Plywood

葉民權(Min-Chyuan Yeh) ； 陳宥呂(Yu-Lu Chen) ； 何季蓉(Ji-Rong Her)

《林產工業》 18卷2期 (1999/06) Pp. 203-213

摘要

本研究主要是探討國產及進口合板在工程應用及結構分析中有關之木質板剪斷性質。合板之板厚度方向剪斷強度、非破壞性剪斷係數及水平剪斷強度試驗之進行係參考ASTM方法及有關簡化程序進行，分析2.7 mm，6.4 mm，8.7 mm，11.9 mm及14.8 mm等不同厚度合板之差異，並探討合板等級及種類的影響。結果顯示國產普通合板中14.8 mm厚合板之最大板厚剪斷強度為最優，其值為81.4 lgf/cm^2，較8.7 mm厚合板高38%，而三種國產不同厚度之A級與B級合板之間，並不因面板品質與中板的缺點而造成剪斷強度之降低。印尼進口之柳桉合板則以2.7 mm厚度合板為最優，較其他四種較厚的普通合板高27%。在合板之剛性係數中，國產合板則較印尼柳桉合板為優，在不同厚度方面又以2.7 mm厚度柳桉合板為最低。國產A級合板之剛性係數則較B級為優。以非破壞性試驗所測定之合板剪斷係數中，國產及印尼柳桉2.7 mm厚度合板較優，分別為其他厚度合板之3.33倍及5.15倍。15 mm厚普通合板與防水合板的剪斷係數則無明顯差異。國產A級合板之水平剪斷強度為27 kgf/cm^2，較柳桉合板高20%，在等級間則無明顯差異，在比例限界時之合板水平剪斷應力約為最大破壞強度的65%。合板依CNS 8060-02032測定之膠合剪力平均為10.4 kgf/cm^2，僅為大試材測得平均水平剪斷強度之44%。

關鍵字

合板 ； 板厚剪斷強度 ； 剪斷係數 ； 水平剪斷強度

並列摘要

The purpose of this study is to investigate the shear characteristics of panels related to the engineering application and structural analysis procedure for the domestic and imported plywood. The evaluation on the properties of shear throuht-the-thickness, shear modulus, and rolling shear of plywood is performed according to ASTM testing procedures and simplified approaches. The results showed that the domestic 14.8 mm thick plywood has the highest values of shear through-the thickness, 81.4 kgf/cm^2, which is 38% higher than that of 8.7 mm thick plywood. And there is no difference in shear strength between plywood specimens with different grades. The shear through-the-thickness of imported 2.7 mm thick lauan plywood is 27% higher than those of thicker plywood specimens. The modulus of rigidity of domestic plywood specimens is superior to those of imported lauan plywoods and the lowest value can be found from 2.7 mm thick lauan plywood specimens among different thickness of panels. The shear modulus evaluated based on the nondestructive tests for domestic and imported lauan 2.7 mm thick plywood specimens are 3.33 and 5.15 times higher than those thicker plywoods, respectively. Furthermore, the difference in shear modulus was not found between common plywood and water resistant plywood. The average rolling shear of domestic plywood specimens with grade A is 27 kgf/cm^2, which is 20% higher than that of lauan plywood. The rolling shear stress, plywood specimens evaluated at proportional limit is about 65% of the maximum rolling shear strength. The shear strength of small plywood specimens evaluated based on CNS 8060-02032 method is 10.4 kgf/cm^2, which is only about 44% of rolling shear.

並列關鍵字

Plywood ； Shear through-the-thickness ； Shear modulus ； Rolling shear