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http://dx.doi.org/10.5658/WOOD.2017.45.1.20

Anisotropy of Softwood Structural Lumber Using The Elastic Modulus Determined by The Ultrasonic Nondestructive Method  

Oh, Sei-Chang (Department of Forest Resources, Daegu University)
Publication Information
Journal of the Korean Wood Science and Technology / v.45, no.1, 2017 , pp. 20-27 More about this Journal
Abstract
The aim of this paper is to present the modulus of elasticity of $E_L$, $E_R$, $E_T$ along three principal axis of softwood dimension lumber by nondestructive method. Ultrasonic measurement was carried out on defect free wood samples taken by the Japanese Larch, SPF (spruce-pine-fir) and Hem-fir $2{\times}4s$. The ultrasound velocities were measured to calculate young's moduli and it was derived elastic constants for each wood samples using the ultrasound velocities and densities of wood. From the test, $E_L$ was much greater than $E_R$ and $E_T$. $E_R/E_T$ ratios were about 1.3. The high density wood had high young's moduli in three principal axis and the difference in young's moduli between species was greater in transverse direction than longitudinal direction. The anisotropy of the lumber was presented through the calculated elastic moduli and compliances matrix in diagonal term were determined by inverting the stiffness matrix.
Keywords
ultrasonic measurement; young's moduli; anisotropy; stiffness matrix; Japanese Larch; spruce-pine-fir; Hem-fir;
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  • Reference
1 Arx, G.V., Arzac, A., Jose, M.O., Fonti, P. 2015. Assessing Conifer Ray Parenchyma for Ecological Studies: Pitfalls and Guidelines. Front Plant Science 6, article 1016: 1-10.
2 Bergander, A., Salme, L. 2000. Variations in transverse fibre wall properties: relations between elastic properties and structure. Holzforschung 54(6): 654-660.   DOI
3 Bodig, J., Jayne, B.A. 1982. Mechanics of wood and wood composites. Van Nostrand Reinhold, New York, p. 712.
4 Bucur, V., Archer, R.R. 1984. Elastic constants for wood by an ultrasonic method. Wood Science and Technology 18: 255-265.   DOI
5 Bucur, V. 1995. Acoustics of wood. CRC Press, Boca Raton, p. 284.
6 Bucur, V., Declercq, N.F. 2006. The anisotropy of biological composites studied with ultrasonic technique. Ultrasonics 44: 829-831.   DOI
7 Castagnee, J., Jenkins, T., Sachse, W., Baste, S. 1990. Optimal determination of the elastic constants of composite materials from ultrasonic wave-speed measurements. Journal of Applied Physics 67(6): 2753-2761.   DOI
8 Kollmann, F.F.P., Cote, W.A. 1968. Principles of wood science and technology: Solid wood. Springer-Verlag, New York, p. 592.
9 Jeong, S.-H., Park, B.-S. 2008. Wood properties of useful tree species grown in Korea. Korea Forest Research Institute Research Paper No. 29. p. 390.
10 Keunecke, D., Sonderegger, W., Pereteanu, K.. Luhi, T., Niemz, P. 2007. Determination of Young's and shear moduli of common yew and Norway spruce by means of ultrasonic waves. Wood Science and Technology 41(4): 309-327.   DOI
11 Sakai, H., Takagi, K., Minamisawa, A. 1987. Ultrasonic properties in wood. Japanese Journal of Applied Physics, 27. Supplememnt 27-1: 55-57.