侧压型竹层板用竹条分级研究  

Research on classification of bamboo strips for laminated bamboo produced by lateral pressuring

作　　者：谢力生[1] 陶钧 廖彬彬 刘嘉诚 朱芳钰 XIE Lisheng;TAO Jun;LIAO Binbin;LIU Jiacheng;ZHU Fangyu(College of Materials Science and Engineering,Central South University of Forestry and Technology,Changsha 410004,China)

机构地区：[1]中南林业科技大学材料科学与工程学院,长沙410004

出　　处：《林业工程学报》2023年第6期43-49,共7页Journal of Forestry Engineering

基　　金：湖南省高校创新平台开放基金(19K110);湖南省重点研发计划(2020NK2021)。

摘　　要：按照GB/T 17657—2022《人造板及饰面人造板理化性能试验方法》中的三点弯曲法,先测试竹条径向两面(近竹青面和近竹黄面)各节间和节部的抗弯弹性模量,然后将试件从宽度方向一分为二,测试其各对应位置的弦向抗弯弹性模量和静曲强度。探讨竹条节间中心位置不同方向的弹性模量相互之间及其与弦向静曲强度之间的关系,并建立相应的数学模型;分析竹节对竹条弹性模量的影响,确定侧压型竹层板用竹条的实用分级方法;按中间点径向抗弯弹性模量对竹条进行分级,并测试其弦向静曲强度,分析竹条分级的可靠性;将不同等级的竹条分别制备侧压型竹层板试件,测试其静曲强度和抗弯弹性模量,验证竹条分级的有效性。结果表明:通过测量竹条节间径向两面抗弯弹性模量并计算其平均值,可以较准确地推测其弦向抗弯弹性模量值;通过测试竹条某节间径向两面抗弯弹性模量的平均值,可以很好地预测该部位的弦向静曲强度;仅测量竹条中间点(无论是节间还是节部)的径向抗弯弹性模量就能较好地推测出整根竹条的弦向抗弯弹性模量;采用竹条中间点径向抗弯弹性模量分等可以对竹条(弦向静曲强度)进行有效分级;按竹条中间部位的径向抗弯弹性模量对竹条进行分级,其侧压型竹层板的分级效果显著。In this study,the three-point bending method in GB/T 17657-2022“Test methods of evaluating the properties of wood-based panels and surface decorated wood-based panels”was used to test the bending strength of bamboo strips.The flexural modulus of elasticity(MOE)was tested on two radial sides(near the green side and near the yellow side),and then the strips were divided in half from the width direction to test the flexural MOE and static bending modulus and rupture(MOR)in the tangential direction.The relationships between the MOR in different directions and the static bending MOR in the tangential direction at the center of the bamboo strips were investigated,and a mathematical model was established.The influence of bamboo knots on the MOE of bamboo strips was analyzed to determine a practical grading method for lateral pressured bamboo laminates.The grading method involved grading the bamboo strips according to the flexural MOE at the radial midpoint and testing their tangential flexural MOR to analyze the reliability of bamboo strip grading.Finally,the bamboo strips of different grades were separately prepared for lateral pressured bamboo laminates and tested for their MOE and MOR to demonstrate the effectiveness of the grading method.There was a extremely significant linear relationship between the tangential static MOR of bamboo strips and their tangential MOE(r=0.9545)and the mean value of their radial two-sided MOE(r=0.9083),and the tangential static MOR of bamboo strips increased with the increase of tangential MOE and the increase of the mean value of radial two-sided MOE.The MOE and MOR of bamboo laminates made from graded bamboo strips increased proportionally with the increase of the bamboo strip grade.The findings of this study indicated that the radial MOE between bamboo strips can be used to accurately estimate the tangential MOE by calculating its average value.Moreover,the average value of the radial MOE between bamboo strips can be utilized to well predict the tangential static MOR of a bamboo

关 键 词：毛竹 竹条 分级 侧压型竹层板 抗弯性能 

分 类 号：S781.9[农业科学—木材科学与技术]