Measurement of local wood velocites by acoustic microscopy

This paper presents imaging of wood cells and measurements of wood cell wall mechanical properties by a 400 MHz acoustic microscope. The acquired ultrasonic image shows that for our cedar sample the size of the cell and cell wall are typically 40μm and 7μm respectively. V(Z) measurements of cell walls reveal that the p-wave velocity and modulus of elasticity (MOE) of our cell walls are 6098m/s and 55GPa. Using the Voigt model with the area weighting estimated from the acquired images the calculated bulk MOE was determined as 9 to 12GPa. This is in good agreement with the WoodSpec derived value of 10.5GPa.