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

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