摘要: |
以兴安落叶松(larix gmelini)40mm×65mm×4000mm,40mm×90mm×4000mm,40mm×140mm×4000mm的Ⅰc和Ⅲc等级规格材为例,根据美国材料试验协会标准ASTM D4761 05对试样进行抗弯强度测试,研究兴安落叶松规格材抗弯强度在长宽比为18∶1时的长宽比尺寸效应因数.结果表明:兴安落叶松规格材抗弯强度的长宽比尺寸效应因数存在等级间差异;Ⅰc等级的长宽比尺寸效应因数为043,Ⅲc等级的长宽比尺寸效应因数与强度百分位数之间存在线性关系. |
关键词: 兴安落叶松 结构用规格材 抗弯强度 尺寸效应 |
DOI:103969/j.issn1007 9629201404031 |
分类号: |
基金项目:“十一五”国家科技支撑计划项目(2006BAD18D07) |
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Size Effect of Modulus of Rupture for the Larch Dimension Lumber |
ZHAO Xiu1, L Jianxiong2, JIANG Jinghui2, WANG Hongdi1, HUANG Zaihua1
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1.Key Laboratory of Lumber of State Forestry Administration, Heilongjiang Academy of Forestry, Harbin 150081,China;2.Research Institute of Wood Industry, Chinese Academy of Forestry, Beijing 100091, China
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Abstract: |
Flexural properties of larch(larix gmelini) dimension lumber(40mm×65mm×4000mm, 40mm×90mm×4000mm and 40mm×140mm×4000mm, Ⅰc and Ⅲc grade) were tested by using the method of America society for testing and materials ASTM D4761 05. The purpose of the present study is to calculate the size effect parameters of modulus of rupture for the dimension lumber of larch when a span to depth ratio of 18∶1 was adopted for bending specimens. The results indicated that the size effect parameters is different between grades. For Ⅰc grade the size effect parameters is 043 and for Ⅲc grade lumber the relation between size effect parameters and strength level showed linear relationship. |
Key words: larch dimensional lumber modulus of rupture(MOR) size effect |