单调荷载下三层正交胶合木企口节点的剪切性能  

Study on shear performance of 3⁃layer CLT T&G joints under monotonic loading

作　　者：张敬婷 王志强 赵涛 刘艺肖 董惟群 ZHANG Jingting;WANG Zhiqiang;ZHAO Tao;LIU Yixiao;DONG Weiqun(College of Materials Science and Engineering,Nanjing Forestry University,Nanjing 210037,China;College of Forestry and Landscape Architecture,Anhui Agriculture University,Hefei 230036,China)

机构地区：[1]南京林业大学材料科学与工程学院,南京210037 [2]安徽农业大学林学与园林学院,合肥230036

出　　处：《林业工程学报》2020年第4期67-72,共6页Journal of Forestry Engineering

基　　金：国家自然科学基金(31570559);贵州省科技支撑计划(黔科合GY字[2010]3025)。

摘　　要：为了研究3层正交胶合木(CLT)企口连接的连接性能,对3种不同榫头长度的正交胶合木企口连接试件和传统半搭接连接试件进行准静态单调加载剪切测试。分析企口试件的破坏模式,比较企口试件与半搭接试件在承载能力、刚度以及延性方面的改变,并对比3种不同榫头长度对CLT企口节点抗剪性能的影响。测试使用全螺纹自攻螺钉,垂直CLT板宽面单侧打入,企口连接的榫头长度分别为35,50和65 mm,半搭接连接的搭接长度为50 mm。参照欧洲标准EN 26891-1991进行准静态单调加载。结合试验现象和数据进行了分析比较,结果表明:企口试件的主要破坏现象为STS屈服、钉帽拉穿和木材销槽承压破坏,同时,得益于企口连接的剖面形状,试件在整个加载过程中保持了良好的完整性,未发生面外偏转。半搭接试件易发生面外偏转、钉尖拔出、构件分离。3种榫头长度的企口连接相较半搭接连接在最大承载力、初始刚度和延性方面都有提升。榫头最长的TG-65组试件力学性能相对较好,较半搭接HL-50组试件承载力提升23%、初始刚度提升200%、延性系数提升206%。In order to study the mechanical properties of the Tongue and Groove(T&G)joints,quasi-static monotonic shear loading tests were carried out on Cross-Laminated Timber(CLT)T&G joints with three different tenon lengths and traditional CLT half-lapped joints with one overlap length.The failure modes of the T&G specimen were analyzed.The load-carrying capacity,stiffness and ductility of the T&G specimens were compared with those of the half-lapped specimens.The effects of the different tenon lengths on mechanical properties were also investigated.The self-tapping screws(STS)were inserted vertically into one CLT side face.The length of the tenons in the T&G specimen were 35 mm,50 mm,and 65 mm,respectively,and the overlap length of the half-lapped joints was 50 mm.Monotonic loading tests were conducted according to EN 26891-1991.The results were analyzed and compared in the combination of the experimental phenomena and data.It was found that the main failure modes were yielding failure of the STS,embedding failure of the wood specimens,screw head pull-through and screw tip pulling-out.The latter two phenomena indicated that the STS had a“rope effect”.In the half-lapped joints,there was no head pull-through,and only the screw tip pulling-out of the wood specimens.At the same time,benefited from the unique profile of the T&G specimen,the good integrity in the whole loading process was maintained without out-of-plane deflection.Half-lapped specimens were prone to out-of-plane deflection,screw tip pulling out and component separation.The load-carrying capacities,initial stiffness,and ductility of the T&G joints with three tenon lengths were all higher than those of the half-lapped joints.However,the timber of TG-35 group was prone to be split due to the small STS edge distance,and the load-carrying capacity was reduced.The damage of the adhesive layers in some TG-65 specimens also affected the load-carrying capacity.Among the three tenon lengths in this experiment,the specimen with a length of 65 mm had the relatively h

关 键 词：正交胶合木(CLT) 剪切性能 企口连接 承载力 初始刚度 延性 

分 类 号：S784[农业科学—林学]