压力和缝隙对正交胶合木胶层和层间剪切性能的影响  

Effects of Different Pressures and Gaps on Adhesive Layer and Interlaminar Shear Performance of Cross Laminated Timber

作　　者：曲家磊 刘博杨 张焕民 李明月 徐金梅[1] 任海青[1] 龚迎春[1] QU Jialei;LIU Boyang;ZHANG Huangmin;LI Mingyue;XU Jinmei;REN Haiqing;GONG Yingchun(Research Institute of Wood Industry,Chinese Academy of Forestry,Beijing 100091,China;Yantai Bohai Woodworking Machinery Company,Yantai 264000,Shandong,China;Jiangsu Space-O Technology Group Co.,Ltd.,Jingjiang 214500,Jiangsu,China)

机构地区：[1]中国林业科学研究院木材工业研究所,北京100091 [2]烟台博海木工机械有限公司,山东烟台264000 [3]江苏零界科技集团有限公司,江苏靖江214500

出　　处：《木材科学与技术》2025年第1期47-55,共9页Chinese Journal of Wood Science and Technology

基　　金：山东省科技型中小企业创新能力提升工程项目“正交胶合木智能分选与柔性制造集成化装备开发与应用”(2023TSGC0865);“十四五”国家重点研发计划课题“结构用大规格集成材的制造与评价关键技术”(2021YFD2200605)。

摘　　要：采用真空加压和气囊加压制备欧洲云杉(Picea abies)正交胶合木(cross laminated timber,CLT),先采用层板侧面施胶工艺,分析真空加压方式和气囊加压方式以及不同压力(0.4、0.6和0.8 MPa)对CLT胶层剪切性能的影响;再采用层板侧面不施胶工艺,探究相邻层板缝隙宽度(2、4和6 mm)对层间剪切性能的影响规律,基于声发射信号特征判断CLT层间剪切损伤类型及动态演变特征。研究结果表明:真空与气囊加压压力对CLT胶层剪切强度和浸渍剥离存在显著影响;CLT胶层剪切木材破坏模式主要有靠近胶层木材剪切破坏,中间层沿木射线方向呈不连续破坏,以及早晚材轮界面剪切破坏;当气囊加压压力为0.8 MPa,CLT常温浸渍、煮沸浸渍和真空加压浸渍剥离合格率均达到90%以上。层板缝隙宽度对CLT层间剪切强度存在显著影响,当表层和横向层层板缝隙宽度增加至6 mm时,层间剪切强度相对层板侧面施胶(缝隙宽度0 mm)降低了43.7%,横向层从滚动剪切破坏转变为层板滑移和缝隙处裂纹延展到胶层开裂破坏。声发射(acoustic emission,AE)能量变化能够准确地反映CLT层间剪切损伤演化过程:在形变阶段,AE能量信号较少,木材纤维束发生屈曲,张拉型微裂纹开始萌生;在裂纹扩展阶段,AE累计能量呈现直线上升,高RA(rise time/amplitude)值、低AF(average frequency)值的剪切型裂纹信号增多;在破坏阶段:AE能量信号形成局部峰值,高RA值、低AF值的剪切型裂纹信号占比达到22.31%,CLT破裂形式由张拉型破坏向拉剪复合破坏转变。The European spruce was selected to prepare cross laminated timber(CLT)by the vacuum pressure and balloon pressure.Firstly,under the conditions of adhesive application on the side of the laminated board,CLT samples were made under vacuum pressure of 0.1 MPa,and balloon pressures of 0.4,0.6,and 0.8 MPa,respectively.The shear performance of the CLT adhesive layer were tested.Then,using the process of not applying glue to the side of the laminated board,CLT samples were made under balloon pressures of 0.8 MPa with the gap width of 2,4,and 6 mm,respectively.The interlayer shear performance were evaluated.The damage types and dynamic evolution characteristics of CLT interlaminar shear were measured based on acoustic emission signal.The results showed that the pressure had significant effect on the adhesive layer shear strength and vacuum pressure impregnating of CLT.The failure modes of CLT adhesive layer shear mainly included shear failure near the adhesive layer,failure along the wood ray direction in the middle layer,and shear failure at the interface of early wood and late wood.The qualified rate of CLT room-temperature impregnating,boiling impregnating and vacuum pressure impregnating reached above 90%at the 0.8 MPa.The gap widths had a significant effect on the interlayer shear strength of CLT.When the gap widths of the surface layer and transverse layer increased from 0 mm to 6 mm,the interlaminar shear decreased by 43.7%,and the failure mode of transverse layer gradually transformed from rolling shear failure to laminate slip;the gap failure extended to the adhesive layer failure.In addition,the change of acoustic emission(AE)energy precisely reflected the damage evolution of CLT interlaminar shear.The AE energy signal was weak when the wood fiber bundle buckling and the tensile microcracks started to sprout in the deformation stage.In the crack propagation stage,the cumulative AE energy increased linearly,and the shear crack signals with high Risetime/Amplitude(RA)value and low Average Frequency(AF)value incr

关 键 词：正交胶合木 胶层剪切性能 层间剪切性能 声发射 

分 类 号：TU366.2[建筑科学—结构工程]