Effect of Specimen Width on Shear Modulus of Wood Obtained by Flexural Vibration Tests

Authors

  • Yoshitaka Kubojima
  • Mario Tonosaki

Keywords:

Flexural vibration, Goens-Hearmon regression method, shear modulus, specimen width, Timoshenko theory of bending

Abstract

This study proposes a method of determining specimen width to increase the precision of shear modulus with flexural vibration. Free-free flexural vibration tests and modal analyses were conducted on Sitka spruce (Picea sitchensis Carr.) specimens 5-150 mm wide, 10 mm thick, and 300 mm long. The specific shear modulus obtained by Goens-Heamon regression based on the Timoshenko theory of bending varied for a large width. Specimen width to clearly identify resonance frequencies of flexural vibration could be obtained by modal analysis. An equation was also developed to easily determine such specimen width.

References

Akitsu H, Norimoto M, Morooka T (1991) Vibrational properties of chemically modified wood. J Jpn Wood Res Soc 37:590-597.nBrancheriau L (2006) Influence of cross section dimensions on Timoshenko's shear factor—Application to wooden beams in free-free flexural vibration. Ann Sci 63:319-321nCowper GR (1966) The shear coefficient in Timoshenko's beam theory. J Appl Mech 33:335-340.nFukada E (1950) Vibrational study of the wood used for the sound boards of pianos. Nature 166:772-773.nGoens E (1931) Über die Bestimmung des Elastizitätsmodulus von Stäben mit Hilfe von Biegungsschwingungen. Ann Phys 5:649-678.nHase N (1987) A comparison between acoustical physical factors of Honduras Rosewood for marimbas and xylophones and a sensory evaluation of these instruments. J Jpn Wood Res Soc 33:762-768.nHearmon RFS (1948) The elasticity of wood and plywood. His Majesty's Stationary Office, London, UK.nHearmon RFS (1958) The influence of shear and rotatory inertia on the free flexural vibration of wooden beams. Br J Appl Phys 9:381-388.nHutchinson JR (2001) Shear coefficients for Timoshenko beam theory. J Appl Mech 68:87-92.nKataoka A, Ono T (1976) The dynamic mechanical properties of Sitka spruce used for sounding boards. J Jpn Wood Res Soc 22:436-443.nKubojima Y, Yoshihara H, Ohta M, Okano T (1996) Examination of the method of measuring the shear modulus of wood based on the Timoshenko theory of bending. J Jpn Wood Res Soc 42:1170-1176.nKubojima Y, Yoshihara H, Ohta M, Okano T (1997) Accuracy of the shear modulus of wood obtained by Timoshenko's theory of bending. J Jpn Wood Res Soc 42:439-443.nNakao T, Okano T, Asano I (1983) Effect of heat treatment on the loss tangent of wood. J Jpn Wood Res Soc 29:657-662.nNakao T, Okano T, Asano I (1984) Measurement of anisotropic shear modulus by the torsional-vibration method for free-free wooden beams. J Jpn Wood Res Soc 30:877-885.nNorimoto M (1982) Structure and properties of wood used for musical instruments I. On the selection of wood used for piano soundboards. J Jpn Wood Res Soc 28:407-413.nPuchegger S, Bauer S, Loidl D, Kromp K, Peterlik H (2003) Experimental validation of the shear correction factor. J Sound Vibrat 261:177-184.nSobue N (1988) Simultaneous determination of Young's modulus and shear modulus of structural lumber by complex vibrations of bending and twisting. J Jpn Wood Res Soc 34:652-657.nTimoshenko SP (1921) On the correction for shear of the differential equation for transverse vibrations of prismatic bars. Philos Mag 41:744-746.nTonosaki M, Okano T, Asano I (1983) Vibrational properties of Sitka spruce with longitudinal vibration and flexural vibration. J Jpn Wood Res Soc 29:547-552.nYano H, Yamada T, Minato K (1986) Changes in acoustical properties of Sitka spruce due to reaction with formaldehyde. J Jpn Wood Res Soc 32:984-989.nYoshihara H (2009) Comparison of Young's modulus and shear modulus of wood measured by flexural vibration and static bending tests. Wood Ind 64:69-73.n

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Published

2013-04-15

Issue

Number 2 / April 2013

Section

Research Contributions

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