结构用定向刨花板与云杉-松-冷杉规格材混合组坯正交胶合木的抗弯性能  

Flexural Behavior of Hybrid Cross-Laminated Timber Fabricated from Construction Oriented Strand Board and Spruce-Pine-Fir

作　　者：李桥 王志强 梁芝君 李龙 Li Qiao;Wang Zhiqiang;Liang Zhijun;Li Long(College of Materials Science and Engineering,Nanjing Forestry University,Nanjing 210037;Hubei Tianxin Timber Framed Building Manufacturing Co.,Ltd,Hanchuan 431600)

机构地区：[1]南京林业大学材料科学与工程学院,南京210037 [2]湖北天欣木结构房屋制造有限公司,汉川431600

出　　处：《林业科学》2021年第11期158-168,共11页Scientia Silvae Sinicae

基　　金：国家自然科学基金项目(32071700)。

摘　　要：【目的】探究国产结构用定向刨花板(COSB)与云杉-松-冷杉(SPF)规格材混合组坯正交胶合木(HCLT)的抗弯性能,明确组坯结构和层数对HCLT抗弯性能的影响,以拓宽国内正交胶合木(CLT)产品原材料来源、促进COSB在木结构建筑领域的应用。【方法】利用COSB和SPF规格材以不同组坯结构与层板位置混合形成不同层数(3层和5层)、5种组坯结构的CLT和HCLT试件,对试件进行四点弯曲性能测试,评价CLT/HCLT材料主、次方向的抗弯强度、抗弯模量和破坏模式;采用剪切类比法计算抗弯性能理论值,并建立HCLT有限元模型分析HCLT的抗弯性能。【结果】不同组坯结构HCLT破坏模式不同,主方向试件主要为横向层锯材滚动剪切破坏和底层层板拉伸破坏;由于层板侧面未涂胶胶合,次方向试件主要在底层层板缝隙处发生拉伸破坏。HCLT的抗弯性能普遍高于SPF规格材CLT,对于主方向抗弯强度,所有HCLT试件的抗弯强度均高于SPF规格材CLT,与SPF规格材CLT相比(A1组),3层和5层HCLT试件(A3组)的抗弯刚度分别高10%和31%,抗弯强度分别高76%和48%;次方向抗弯性能提升更大,与SPF规格材CLT相比(B1组),3层和5层HCLT试件(B4组)的抗弯刚度分别高447%和83%,抗弯强度分别高118%和40%。随着COSB在HCLT中使用层数增加,HCLT次方向和双向力学性能均得到提升,主、次方向抗弯力学性能差异减少;综合考虑材料经济性和力学性能,A3/B3组坯结构,即仅将COSB作为横向层形成的HCLT材料具有更好的双向弯曲性能。随着CLT层数增加,试件抗弯刚度和次方向抗弯强度增加,主方向抗弯强度降低;采用剪切类比法可较好预测CLT主方向抗弯性能,但由于存在非侧面胶合的横向层等因素影响,次方向力学性能存在一定相对误差,理论值偏于保守;对于次方向试件抗弯性能理论计算,当表层层板为COSB时,可不忽略表层层板作用;建立的有限元模型能较好分析HCLT抗弯�【Objective】In order to explore the feasibility of domestic construction oriented strand board(COSB)used in cross-laminated timber(CLT)production,expand the raw materials source of domestic CLT products,promote the application of COSB in timber structure buildings,and evaluate the influences of configuration and layer number on flexural behavior of CLT,the flexural behavior of hybrid CLT(HCLT)fabricated from COSB and lumber were investigated in this paper.【Method】The HCLT panels with different layer number(three and five layers)and five configurations were fabricated from COSB and SPF(spruce-pine-fir)dimension lumber.The bending strength,bending modulus and failure modes of CLT and HCLT specimens in major and minor strength direction were evaluated by four-point bending test.The theoretical values of bending properties were calculated by shear analogy method,and the finite element models were built to analyze the bending performances of HCLT.【Result】The main failure modes of test specimens in major strength direction were rolling shear failure of transverse layer of lumber and tensile failure of bottom layer.The tensile failure of specimens in minor strength direction was mainly occurred at the gaps between bottom layers due to no edge-gluing.HCLT had higher bending properties than generic CLT.All the bending strength of HCLT in major strength direction were higher than those of generic CLT(group A1).The bending stiffness of the three-and five-layer HCLT specimen(A3 group)were 10%and 31%higher than those of generic CLT(group A1),which were 76%and 48%for bending strength,respectively.The improvement of bending properties was more significant for specimens in minor strength direction.The bending stiffness of three-and five-layer HCLT specimen(group B4)were 447%and 83%higher than those of generic CLT(group B1),which were 118%and 40%for bending strength,respectively.With the increase of the COSB layer number used in HCLT,the bending properties in minor and two-way strength direction of HCLT were improved,a

关 键 词：正交胶合木 混合层板 结构用定向刨花板 弯曲性能 剪切类比法 数值模拟 

分 类 号：S781.2[农业科学—木材科学与技术]