Variation of the dynamic elastic modulus and wave velocity in the fibre direction with other properties during the drying of Eucalyptus regnans F. Muell

Dynamic elastic modulus (E_L) and wave velocity (V) were determined using resonance vibrations from initially green, 100 × 50 mm sample boards of Eucalyptus regnans F. Muell., and after several stages of drying to oven dry. E_L and V were determined from impact induced vibrations and spectral analysis. E_L and V from green wood were positively related to basic density and normal shrinkage, only V was negatively related to green density, and both E_L and V were negatively related to green moisture content and the number of internal checks after drying. The latter relationship has the potential to provide a simple method of segregating highly check prone material. No significant relationships were obtained with collapse. Outside the hygroscopic range, in low shrinkage material, E_L increased little or gradually, while in high shrinkage, collapse prone material, it increased more rapidly, but no clear breakpoint was evident. In the hygroscopic range, E_L increased rapidly in all samples. V increased curvilinearly throughout the entire moisture range, but no difference between collapse prone and non-collapse prone material was observed. Received 16 February 1998