Influence of Aspect Ratio on Rolling Shear Properties of Fast-Grown Small Diameter Eucalyptus Lumber  

作　　者：Tao Gui Shichen Cai Zhiqiang Wang Jianhui Zhou 

机构地区：[1]College of Materials Science and Engineering,Nanjing Forestry University,Nanjing,210037,China [2]Integrated Wood Engineering,University of Northern British Columbia,Prince George,V2L 1R7,Canada

出　　处：《Journal of Renewable Materials》2020年第9期1053-1066,共14页可再生材料杂志（英文）

基　　金：the National Natural Science Foundation of China(Grant No.31570559 and No.51808293);Natural Science Foundation of Jiangsu Province,China(Grant No.BK20180778).

摘　　要：Eucalyptus is a major fast-grown species in South China,which has the potential for producing structural wood products such as cross-laminated timber(CLT).Aspect ratio(board width vs.board thickness)of eucalyptus lumbers is small due to the small diameter of fast-grown eucalyptus wood.To evaluate its rolling shear modulus and strength for potential CLT applications,three-layer hybrid CLT shear block specimens with different aspect ratios(2,4,6),were tested by planar shear test method.Digital image correlation(DIC)was employed to measure the rolling shear strain distribution and development during the planar shear tests.The mean values of rolling shear modulus and strength of eucalyptus lamination were 260.3%and 88.2%higher than those of SPF(Spruce-pine-fir)lamination with the same aspect ratio of 4,respectively.The rolling shear properties of eucalyptus laminations increased as the aspect ratio increased.Aspect ratio had a significant influence on rolling shear modulus compared to rolling shear strength.The high shear strain regions were primarily found around the gaps between segments of cross layer.The quantity of high shear strain regions increased as the aspect ratio of lamination decreased.Other high shear strain regions also occurred around the pith and along the glue line.The sudden failure of specimen occurred in the high strain region.In conclusion,the rolling shear strength and modulus of fast-grown eucalyptus laminations exceed the respective characteristic values for softwoods in the current standard by roughly factors of 3 and 8,indicating great potential for fast-grown eucalyptus wood cross-layers in CLT.

关 键 词：Fast-grown eucalyptus cross-laminated timber rolling shear aspect ratio digital image correlation 

分 类 号：TG1[金属学及工艺—金属学]