Measurement of dynamic modulus of elasticity and damping ratio of wood-based composites using the cantilever beam vibration technique

The non-destructive testing technique has been widely used to determine the dynamic mechanical properties of wood and wood-based composites, such as dynamic modulus of elasticity (Ed) and damping ratio (ζ). The cantilever beam vibration method is a cost-efficient and time-saving technique that was employed in this study to measure Ed and ζ values of three commercial wood-based composites, i.e. plywood (PLW), high density fiberboard (HDF), and oriented strand board (OSB). The Ed and ζ values were determined in light of the spectral analysis on the first natural frequency and the first and fifth amplitudes of vibration in the vertical direction, which was triggered by tapping one end of a specimen free of the support. To verify the values, the static bending tests were conducted. It was found that the Ed values of three kinds of wood composites tested were slightly higher than the static modulus of elasticity (Es). There existed a good linear agreement between Ed and Es. The ζ value of PLW was the largest among three composites, and the OSB showed the lowest ζ.