Vibration Based NDT Methods to Verify Wood Drying Efficiency

Abstract

• The capability of application of fl exural vibration test in nondestructive evaluation of wood drying was studied. Poplar timbers were conventionally kiln dried under three different drying schedules down to the

Effect of artificial inhomogeneity of density and drilling on dynamic properties developed by poplar block species (Populus nigra) jointed with oak wood (Quercus castaneifolia) beams

“…The lower its values, the better its noise conductance therein (Tsoumis 1991). In the past, the values of this factor increased due to the presence of inhomogeneity (Wilcox 1978;Ouis 2004;Hu and Afzal 2006;Aramaki et al 2007;Sedik et al 2010;Roohina et al 2011;Kohantorabi et al 2015). In this research, the joined samples at the central part of the beams (Fig.…”

“…The ACE is a major factor in wood, consisting of dynamic moduli of elasticity, density, and damping capacity as the coefficient and final factor for identifying the flawlessness of wood (Kohantorabi et al 2015). In this study, similar to the process used by Kohantorabi et al (2015), during the process of discovering inhomogeneity in dried woodworks through different wood drying programs, it was found that the samples with more defects were of lower ACE, with the exception that there, the effect of the location of defect and inhomogeneity was not identifiable, while here it was identifiable through appropriate correlations according to the obtained results and the vibration node and antinode locations (Fig. 6).…”

“…The results indicated that except for the effect of mass addition in the initial sections of the beam, in other parts, the process of adding mass has a significant effect on the obtained modulus of elasticity, but they could not discover the effect of artificial inhomogeneity location on dynamic modulus of elasticity. Kohantorabi et al (2015) assessed the effect of moisture and temperature variations in three wood drying programs and compared the obtained results with static tests. They concluded that the resulting variation in acoustical converting efficiency (ACE) is the most appropriate criterion in assessing the efficiency of wood drying programs adopted for this type of beam and identified the resulting inhomogeneities, like the cracks during the wood drying process.…”

Modelling of Drying Curves of Spruce, Beech, Willow and Alder Particles

“…Hence, reducing energy consumption, besides product quality, would be highly important for drying the raw materials used in industry (Zarea Hosseinabadi et al, 2012). Improvements in the wood drying process are accompanied by better understanding of the drying process (Kohantorabi et al, 2015).…”