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

• Published in: Wood science and technology 2001-04, Vol.35 (1-2), p.157-166
• Main Author: ILIC, J
• Format: Article
• Language: English
• Subjects: Applied sciences; Collapse; Drying; Drying ovens; Eucalyptus; Exact sciences and technology; Mechanical properties; Mechanical woodworking and drying; Moisture content; Polymer industry, paints, wood; Shrinkage; Spectral analysis; Spectrum analysis; Storage modulus; Velocity; Vibrations; Water content; Wave velocity; Wood; Wood. Paper. Non wovens
• ISSN: 0043-7719; 1432-5225
• DOI: 10.1007/s002260000075

Dynamic elastic modulus (EL) 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. EL and V were determined from impact induced vibrations and spectral analysis. EL and V from green wood were positively related to basic density and normal shrinkage, only V was negatively related to green density, and both EL 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, EL 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, EL 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.