摘要
该文以经过120 d、温度90℃条件下窑干干燥处理的56根日本柳杉人工林结构材(110 mm×55 mm×2 500 mm)作为测试试件,介绍了一种利用激光测距系统测量顺纹抗拉弹性模量的方法.首先将试件含水率调至15%,在抗拉试验开始前采用纵向基频振动方法(FFT)得到试件的动态弹性模量(Efr),再利用由激光测距仪、数据采集器和计算机处理系统组成的激光测距系统,测定了顺纹抗拉弹性模量(Et),最后破坏试件完成顺纹抗拉强度(σt)的测定.对Efr、Et和tσ相互关系的比较分析表明,Et的平均值比FFT方法得到的Efr的平均值小7.8%(0.63GPa);Et与Efr具有很好的相关性,相关系数R为0.971,在0.001水平上呈显著相关;Et和σt的相关系数R为0.727,也在0.001水平上呈显著相关.足尺试件的顺纹抗拉测试结果表明,激光测距方法可以准确地测量结构材在顺纹受拉时发生的拉伸变形,从而得到可靠的抗拉弹性模量试验结果.
The objective of this paper is to introduce a laser measurement method to obtain the modulus of elasticity（MOE） in tension parallel to grain of structural lumber.Fifty-six pieces of Cryptomeria japonica D.Don plantation lumber（110 mm×55 mm×2 500 mm）,dried at 90℃ temperature in kiln for 120 days,were selected as the testing specimens.After adjusting the moisture content to 15%,the dynamic MOE（Efr） of all pieces was measured based on longitudinal vibration in fundamental frequency（FFT）.A laser measurement system consisting of laser meter for tensile deformation,data logger and computer analyzer was then applied to measure tension MOE（Et） of lumber.Meanwhile,tension strength（σt） of lumber was obtained when pieces were in failure at maximum load.The results indicated that the average Et was 7.8%（0.63 GPa） less than Efr.Statistical linear regression analyses revealed that useful relationship was evident among Et,Efr and σt（P〈0.001）.The correlation coefficient was 0.971 between Et and Efr,and 0.727 between Et and σt.The tensile testing results demonstrated that the laser measurement method could be used to obtain precise tensile deformation for reliable MOE in tension parallel to grain of structural lumber.
出处
《北京林业大学学报》
EI
CAS
CSCD
北大核心
2007年第6期172-175,共4页
Journal of Beijing Forestry University
基金
中日政府间合作JICA项目"中国人工林木材研究"
关键词
激光测距方法
日本柳杉
结构材
顺纹抗拉弹性模量
顺纹抗拉强度
laser measurement method,Cryptomeria japonica D.Don,structural lumber,tensile modulus of elasticity parallel to grain,tension strength parallel to grain
作者简介
殷亚方，博士，副研究员．主要研究方向：木材结构和利用．电话：010—62889468 Email：yafang@caf．ac．cn 地址：100091北京颐和园后中国林业科学研究院木材工业研究所．
