木材科学与技术2025，Vol.39Issue(1)：47-55,9.DOI:10.12326/j.2096-9694.2024093
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
摘要
Abstract
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 increased.In the failure stage,the AE energy appeared the linear mutation,and the ratio of shear crack signals with a high RA value and a low AF value reached 22.31%.The fracture form of CLT changed from tensile failure to tensile-shear compound failure.关键词
正交胶合木/胶层剪切性能/层间剪切性能/声发射Key words
cross laminated timber/adhesive layer shear performance/interlaminar shear performance/acoustic emission(AE)分类
土木建筑引用本文复制引用
曲家磊,刘博杨,张焕民,李明月,徐金梅,任海青,龚迎春..压力和缝隙对正交胶合木胶层和层间剪切性能的影响[J].木材科学与技术,2025,39(1):47-55,9.基金项目
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) （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). （2021YFD2200605）
