Application of Self-tapping Screws for Reinforcing the Shear Resistance Performance of Glulam Beam-Column Connections

自攻螺絲應用於集成材梁柱接合剪斷抵抗性能之補強研究

葉民權(Min-Chyuan Yeh) ； 林玉麗(Yu-Li Lin) ； 鍾佩芬(Pei-Fen Zhong) ； 陳怡安(Yi-An Chen)

《台灣林業科學》 34卷2期 (2019/06) Pp. 113-125

https://doi.org/10.7075/TJFS.201906_34(2).0004

摘要

To reduce the risk of early wood split failure at a timber connection, the application of self-tapping screws was introduced as a reinforcement technique in this study. A lap-joined connection which was assembled using Japanese cedar structural glulam beam and column members was used to investigate the effect of reinforcement with self-tapping screws on the shear resistance capacity of the connections. Results showed that the maximum shear resistance capacities of connections reinforced with 1 or 2 pairs of self-tapping screws were 2.21- and 2.35-fold, respectively, that of an unreinforced connection. Ductility ratios of 5.70~9.88 were obtained for retrofitted and pre-reinforced connections to change the brittle behavior of an unreinforced connection. Adequate ductility was found in lapped connections which were retrofitted or pre-reinforced using 2 pairs of self-tapping screws. The shear resistance performance of the retrofitted connections using self-tapping screws showed similar effects to those of pre-reinforced connections. Energy dissipation tremendously increased from 35.73 to 1923.2 kN．mm as the connections were pre-reinforced or further retrofitted with self-tapping screws in the direction perpendicular to the wood grain. Higher characteristic values and allowable shear capacities of lapped connections were obtained through the use of self-tapping screws to effectively control wood splitting and hence reduce variations in the shearing resistance of the connections.

關鍵字

connection ； self-tapping screw ； structural glulam ； shear resistance ； reinforcement

並列摘要

為降低在木材接合處之早期劈裂破壞風險，本研究採用自攻螺絲做為補強技術之運用。在研究中以柳杉結構用集成材為梁柱構材進行搭接組合，用以探討自攻螺絲在接合部位的剪斷抵抗容量之補強效果。結果顯示，在接合部位以1對或2對自攻螺絲補強之條件，其接合之最大剪斷抵抗容量分別為接合部位未經補強者之2.21及2.35倍。接合部位破壞後補強或預先經過自攻螺絲補強條件之塑性率為5.70～9.88，可以改善接合部位未經補強條件的脆性之結構行為，其中以2對自攻螺絲補強條件之接合有較適當之塑性率。當接合部位破壞後再以自攻螺絲補強的之剪斷抵抗性能，與接合部位預先進行補強條件亦有相近的效果。接合部位在垂直木理方向以自攻螺絲進行補強，無論是採用預先補強或是破壞後再予以補強之方式，接合部位之能量散逸可自35.73 kN．mm大幅提高至1923.2 kN．mm。透過自攻螺絲之補強有效控制搭接部位之木材劈裂及降低接合之變異，可以得到較高的特徵值與容許剪斷容量。

並列關鍵字

接合 ； 自攻螺絲 ； 結構用集成材 ； 剪斷抵抗 ； 補強