弧面竹青抗拉性能试验  

Experimental study on tensile properties of the arc outer green skin of bamboo

作　　者：梅诗意 赵东晖 孟鑫淼 齐晗笑 高颖[1] MEI Shiyi;ZHAO Donghui;MENG Xinmiao;QI Hanxiao;GAO Ying(College of Material Science and Technology,Beijing Forestry University,Beijing 100083,China;Department of Civil Engineering,Beijing Forestry University,Beijing 100083,China;Department of Architecture and the Built Environment,Lund University,Lund 22363,Sweden)

机构地区：[1]北京林业大学材料科学与技术学院,北京100083 [2]北京林业大学土木系,北京100083 [3]隆德大学建筑与建筑环境学院,瑞典隆德22363

出　　处：《林业工程学报》2022年第3期60-66,共7页Journal of Forestry Engineering

基　　金：国家自然科学基金(51908038,31770602);国家重点研发计划(2017YFC0703503)。

摘　　要：为探究原竹弧面竹青的截面识别方式及其抗拉性能的影响因素,在竹根、竹中与竹梢3种高度取材,削去原竹表面蜡质层后,制作弧面竹青试件。基于Ostu算法对弧面竹青试件进行截面识别,计算截面面积、截面维管束面积占比等关键参数;开展抗拉性能测定,分析弧面竹青抗拉性能与维管束面积占比、取材高度、试件厚度及含水率之间的关系,分析竹青维管束和基质等细观构造的抗拉性能。结果表明:原竹弧面竹青试件的维管束面积占比与试件取材高度呈正相关,与试件厚度呈负相关,不同试件的离散性很高,弧面竹青自身条件和加工工艺都会对截面识别产生较大影响;试件的顺纹抗拉强度和弹性模量试验值,与试件取材高度呈正相关,与试件厚度呈负相关,经含水率修正后,12%含水率下竹青的抗拉强度增大,弹性模量减小。提出了不同含水率下基于截面维管束面积占比的竹青顺纹抗拉弹性模量计算公式,可用于弧面竹青弹性模量的预测;利用竹青细观构造与宏观力学性能的关系式,计算得维管束和基质的顺纹抗拉弹性模量分别为48.16和7.57 GPa。The outer green skin of bamboo has the advantages of high wear resistance,low thickness swelling rate and high strength.The outer green skin of bamboo has been used in the wind turbine blade,floor panel and other fields.However,the utilization rate of the outer green skin of bamboo is low in the practical application.The wax layer on the surface of the arc outer green skin of bamboo is not good for processing and gluing.Moreover,the mechanical properties are affected by many factors.The bamboo height of sampling and the thickness of bamboo specimens affect the area ratio of vascular bundles in the cross section of specimens,and further impact the tensile properties of the arc outer green skin of bamboo.The accuracy of the cross-section identification would influence the evaluation of the arc outer green skin.The tensile properties of specimens change with the moisture contents as well.This study explored the cross-section identification method of the arc outer green skin of bamboo and the influencing factors of tensile properties.The arc outer green skin was taken from the root,middle and tip of bamboo.After peeling off the wax layer on the surface of the arc outer green skin,this study identified the cross section of the specimens and calculated the section area and the area ratio of vascular bundles.The tensile tests of specimens were carried out to analyze the relationship among the tensile properties of bamboo,the area ratio of vascular bundles,the bamboo height of sampling,the thickness of specimens and the moisture content.The tensile properties of vascular bundles and parenchyma were examined.The results showed that the area ratio of vascular bundles,tensile strength and elastic modulus of the arc outer green skin were positively correlated with the bamboo height of sampling,and negatively correlated with the thickness of the specimens.When the moisture content was 12%,the tensile strength increased,and the elastic modulus decreased compared to the original moisture contents.The estimation of longitudinal

关 键 词：原竹 弧面竹青 OSTU算法 维管束识别 抗拉性能 

分 类 号：S781.9[农业科学—木材科学与技术]