直交集成板金屬連結件接合之剪斷抵抗性能探討

Investigation of the Shear Resistance Performance of Cross-Laminated Timber Connections Using Mechanical Connectors

葉民權(Min-Chyuan Yeh) ； 宋雲煒(Yun-Wei Sung) ； 林玉麗(Yu-Li Lin)

《台灣林業科學》 34卷4期 (2019/12) Pp. 235-262

https://doi.org/10.7075/TJFS.201912_34(4).0002

摘要

本研究開發鋁合金連結件並以自攻螺絲為扣件應用於直交集成板之接合，探討不同連結件型式、不同自攻螺絲直徑及配置數量，對接合剪斷抵抗之影響。利用國產柳杉製造對稱異等級直交集成板，並考量南方松異樹種製造以及不同木理方向受力條件之影響。結果顯示在最大剪斷容量方面，以T型及平板型連結件進行之直交集成板接合分別優於以L型連結件接合者51及43%，在接合初始剛性方面亦為後者之2.8及6.1倍。以直徑6 mm自攻螺絲18支配置增加至28支數量進行接合時，L型連結件接合之最大剪斷容量及初始剛性可分別提高47及42%；以直徑8 mm自攻螺絲12支配置增加至18支數量時，則分別可提高34及61%。在相同的自攻螺絲配置數量下，以8 mm直徑自攻螺絲接合者之最大剪斷容量及降伏容量分別優於以6 mm直徑接合者42及36%。柳杉直交集成板之接合剪斷抵抗性能與南方松異樹種直交及成板相近。另外，只有6 mm自攻螺絲以28支配置時，其接合才有顯示垂直木理方向載重之最大剪斷容量及降伏容量高於以平行木理方向之載重方式。當連結件之自攻螺絲配置數量增加時，CLT接合部之能量散逸平均可以增加59%。以鋁合金連結件配合自攻螺絲為扣件之直交及成板接合的塑性率介於2.2～8.4，其中以平板型連結件之接合延展性為最高。

關鍵字

直交集成板 ； 自攻螺絲 ； 接合 ； 剪斷抵抗

並列摘要

Aluminum alloy connectors were developed and applied to cross-laminated timber (CLT) connections with fasteners of self-tapping screws (STSs) in this study to investigate the effects of connector types, and the diameter and number of STSs on the shear resistance performance of CLT connections. The CLT of heterogeneous-grade construction was made using Cryptomeria japonica plantation timber mixed with southern pine (Pinus spp.). Effects of the different loading directions along the wood grain were also considered. Results showed that maximum shear capacities of CLT connections assembled with T-type and plate-type connectors were 51 and 43%, respectively, higher than that of a CLT connection with angle bracket connectors. The initial stiffness of the CLT connections assembled with these 2 types of connectors was also found to be 2.8- and 6.1-times higher, respectively, than the CLT connection with angle bracket connectors. Both the maximum shear capacity and the initial stiffness of CLT connections fastened with 6-mm STSs increased 47 and 42%, respectively, as the numbers of STSs applied increased from 18 to 28 during connection assembly. Increases of 34 and 61% in the maximum shear capacity and initial stiffness, respectively, of CLT connections were found as the numbers of 8-mm STSs applied increased from 12 to 18. It was also found that the shear resistance performance of a Japanese cedar CLT connection was close to that of a southern pine-mixed CLT connection. A higher maximum shear capacity and yield shear capacity of a CLT connection were found only in the case fastened with 28 6-mm STSs when the loading direction was applied perpendicular to the wood grain at the connection instead of parallel to the wood grain. The average energy dissipation of the CLT connections increased 59% when a connector was assembled with more STSs. Ductility ratios between 2.2 and 8.4 were obtained when CLT connections were assembled with aluminum alloy connectors using self-tapping screws, and the most ductile behavior was found for a connection assembled with plate connectors.

並列關鍵字

cross-laminated timber ； self-tapping screw ； connection ； shear resistance