瞬态激励法动态测试重组竹弹性模量、剪切模量和泊松比  

Dynamic testing of elastic modulus,shear modulus and Poisson's ratio of bamboo scrimber by transient excitation method

作　　者：徐齐云 谷晓雨 王正 陈林碧 许斌 陈清平 XU Qiyun;GU Xiaoyu;WANG Zheng;CHEN Linbi;XU Bin;CHEN Qingping(College of Materials Science and Engineering,Nanjing Forestry University,Nanjing 210037,China;Fujian Bamboo Voya Co.Ltd.,Yongan 366023,China;Fujian Xinhengda Compartment Backplane Co.Ltd.,Sanming 366035,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]福建省有竹科技有限公司,永安366023 [3]福建鑫恒达车厢底板有限公司,三明366035

出　　处：《林业工程学报》2023年第5期70-78,共9页Journal of Forestry Engineering

基　　金：2021年江苏省现代农业产业单项技术研发项目(CX(21)3049)。

摘　　要：重组竹是一种竹质新材料,其是以竹束为构成单元,经干燥与施胶后于模具中胶合而成的一种型材,完全弥补了原生竹材的结构缺陷。重组竹拥有良好的力学性能、优良的质感以及较高的美学价值,且其本身为绿色环保、可持续供给的生物质材料,因此作为建筑材料的潜力极强。弹性常数是衡量重组竹作为建筑材料的力学性能重要指标,为了快速、简便、无损、准确地检测重组竹材料的弹性常数,分别采用自由板和悬臂板瞬态激励法动态测试了重组竹试件的弹性模量E、剪切模量G和泊松比μ,利用静态四点弯曲法试验验证了重组竹动态弹性模量、剪切模量和泊松比的准确性和可靠性,并对重组竹整板质量等级、均质性和尺寸效应等进行了机理分析与评价。结果表明,重组竹的动态弹性模量、剪切模量和泊松比均值分别为11797 MPa,1579 MPa和0.311,符合GB/T 40247—2021《重组竹》中结构用重组竹的要求。重组竹为各向异性材料,动、静态法测得的重组竹试件弹性常数一致,且本动态测试法相较于其他传统方法具有快捷、便利、重复性好和精度高等优势。Bamboo is a green,low-carbon,fast-growing,easily renewable,and degradable biomass material.Although bamboo fiber has high strength,it has been limited used in the field of modern constructions due to its characteristics and structure of hollow and thin walls.Bamboo scrimber is a new structural bamboo product,which uses bamboo bundles as the constituent unit and is a kind of profile formed in the mold after drying and sizing,which completely makes up for the structural defects of the original bamboo.Bamboo scrimber has good mechanical properties,excellent texture,and high aesthetic value,so its potential as a building material is extremely promising.The elastic constant is an important indicator to measure the mechanical properties of bamboo scrimber as a building material.In order to quickly,simply,non-destructively and accurately detect the elastic constant of the bamboo scrimber material,the elastic modulus E,shear modulus G,and Poisson's ratio μ of the bamboo scrimber specimens were dynamically tested by the free plate and cantilever plate transient excitation methods.The static four-point bending method was used to verify the accuracy and reliability of the dynamic elastic modulus,shear modulus,and Poisson's ratio of the bamboo scrimber.The mechanism analysis and evaluation of the quality grade,homogeneity,and size effect of the whole bamboo scrimber boards were carried out.The results showed that the longitudinal dynamic elastic modulus of bamboo scrimber free board,free beam and cantilever plate in this study were 12019,11216 and 11797 MPa,respectively,and the transverse dynamic elastic modulus were 3230,3554 and 3401 MPa,respectively.The longitudinal shear modulus of the free plate and the cantilever plate were 1559 and 1579 MPa,respectively,and the transverse shear modulus were 1551 and 1561 MPa,respectively.Measured by the cantilever plate,the longitudinal and transverse Poisson's ratios were 0.311 and 0.105,respectively.The longitudinal elastic modulus,shear modulus and Poisson's ratio obtained by the

关 键 词：重组竹 弹性常数 动态测试 静态验证 自由板瞬态激励 悬臂板瞬态激励 四点弯曲法验证试验 

分 类 号：S781.9[农业科学—木材科学与技术]