柳杉結構用集成村之螺栓接合抗拉強度

Tensile Strength of Bolt Joints for Structural Glulam Members Made of Japanese Cedar

葉民權(Min-Chyuan Yeh) ； 王栢村(Bor-Tsuen Wang) ； 吳康正(Kang-Cheng Wu)

《台灣林業科學》 22卷2期 (2007/06) Pp. 101-111

https://doi.org/10.7075/TJFS.200706.0101

摘要

本研究以柳杉造林木開發作為結構用集成材，探討大尺寸木質構材之螺栓接合性能，柳杉集成元斷面為20×100mm，以RPF樹脂膠合成集成材，並利用強度試驗機進行實大尺寸抗拉試驗，分析構材接合特性以及各試驗條件對於接合強度之影響，其中試驗條件之螺栓標定直徑分別為15、18mm；每支集成材單邊之螺栓接合使用數量為2、4、6支。結果顯示，就單支構件使用螺栓數目而言，柳杉集成材使用4及6支15mm螺栓最大抗拉承載力分別為使用螺栓數目2支者158、2.68倍，而18mm螺栓則為2.12、2.90倍，最大可達32603kgf，同時發現使用螺栓支數對於接合性質之影響遠大於螺栓直徑之影響，15及18mm螺栓之單支最大抗拉承載力分別為5389及5671kgf，其平均最大承載強度分別為346及304kgf cm^(-2)，降伏承載強度分別為233及241kgf cm^(-2)，利用ANSYS有限元素分析模擬試材在最大載重之10%範圍下其應力以及螺栓孔周邊應變分布情形，結果顯示最大應力位置與實際破壞位置相符，其中除螺栓孔周邊有應力集中外，且因螺栓配置位置而有所不同，愈近端部其壓縮應力愈大，試材中央均呈抗拉應力。

關鍵字

柳杉 ； 集成材 ； 螺栓 ； 接合強度 ； 有限元素分析

並列摘要

Full-sized structural glued laminated timbers (glulams) were developed using Japanese cedar plantation wood to investigate the performance of bolt joints in this study. The glulams were assembled with laminae 20×100mm in size using resorcinol-phenol formaldehyde (RPF) resin adhesives. Effects of bolt size, i.e., 15 and 18 mm in nominal diameter, and the number of bolts, i.e., 2, 4, and 6 bolts, on the joint strength and joint characteristics of glulam members were investigated through tensile tests. The results indicated that the maximum tensile capacities of glulam joints fastened with 4 and 6 bolts of 15-mm diameter were 1.58 and 2.68 times those of joints assembled with 2 bolts, respectively, while 2.12 and 2.90 times the maximum tensile capacities were found for joints assembled with 18-mm bolts, which reached a maximum of 32,603 kgf. The effect of the number of bolts on the joint performance of glulam members showed greater influence than did bolt size. The maximum tensile capacities per single bolt was 5389 and 5671 kgf for the 15- and 18-mm bolt connections, respectively. The maximum embedded strengths of glulam joints assembled with 15- and 18-mm bolts were 346 and 304 kgf cm^(-2), and yielded embedded strengths of 233 and 241 kgf cm^(-2), respectively. The stress and strain distributions around bolt holes showed correspondence between the ANSYS finite element simulation under 10% maximum loads and the actual failure locations of specimens. The stress changed among bolt locations in the glulam joints and also showed stress concentration around the bolt holes. Higher compressive stress occurred near the end of the stressed members, while the tensile stress was distributed in the middle of the glulam members.

並列關鍵字

Japanese cedar ； glulam ； bolt ； joint strength ； finite element analysis