Determining shear modulus of thin wood composite materials using a cantilever beam vibration method

Shear modulus (G) of thin wood composite materials is one of several important indicators that characterizes mechanical properties. However, there is not an easy method to obtain this value. This study presents the use of a newly developed cantilever beam free vibration test apparatus to detect in-plane G of thin wood composite materials by measuring the first order free vibration cantilever specimens and its logarithmic decrement of vibration. Six sets of commercially purchased thin wood composite materials having three different fiber types were tested. A significant linear correlation was found between in-plane G and bending modulus of elasticity (MOE) from cantilever-beam free vibration test and MOE was shown to be approximately two times of in-plane G. This was in full agreement with previous findings by other researchers. The study demonstrated that the cantilever beam free vibration method could be widely used to obtain in-plane G easily for thin wood composite materials.