The objective of this research was to determine the influence of wood species (Fagus sylvatica L. and Populus tremula L.), thickness (4, 6, 10, 18 mm), and degree of densification (0%, 10%, and 20%) on the impact bending strength (IBS) and Brinell hardness (BH) in the radial direction. Three-factor analysis of variance confirmed that the difference in IBS was significantly related to the wood species and wood thickness. Wood densification did not have a significant effect on IBS. In addition, beech wood exhibited higher IBS values than aspen wood. The IBS values increased proportionally with increasing thickness. All factors affecting Brinell hardness were statistically significant, although thickness had the smallest influence overall. The Brinell hardness values were substantially higher in beech wood than aspen wood, and in some cases were more than three times greater. On the other hand, densification exhibited a more positive effect on increasing Brinell hardness for aspen wood than beech wood.
Keywords
INTRODUCTIONWood is generally recognized as one of the most important renewable resources and among the most versatile and widely used materials. On the other hand, much of its uses depend on the species, because while some tree species are used almost everywhere, others have limited application. The application of wood is directly influenced by its physical and mechanical properties.European beech (Fagus sylvatica L.) is a native wood that grows throughout Europe (Eilmann et al. 2014). Beech is one of the most commonly used hardwoods in Europe (Pöhler et al. 2006;Gryc et al. 2008) for furniture, floors, toys, veneer products, and musical instruments, as well as for the production of stairs, cladding, and glued loadbearing elements in construction (Ohnesorge et al. 2010;Aicher and Ohnesorge 2011;Guntekin et al. 2014). On the other hand, European aspen (Populus tremula L.) wood has only occasional uses. In the woodworking industry, aspen is used in the manufacturing of wood-based materials (plywoods, particle, and flakeboards), in the furniture industry for underlying veneers or surface veneers for backside or nonvisible surfaces (Kärki 2001), and for the facings of ceilings or saunas where high strength or hardness are not necessary (Möttönen et al. 2015). In the past, aspen was primarily used for the production of matches; currently, it has application in the production of biomass fuel, paper, and pulp (Kärki 2001; Heräjärvi and Junkkonen 2006).
PEER-REVIEWED ARTICLEbioresources.com Gašparík et al. (2016). "IBS and BH of hardwoods," BioResources 11(4), 8638-8652. 8639The uses for these wood species are closely related to their mechanical properties. Mechanical properties differ by wood type because they depend not only on the type of loading (tension, pressure, and bending), but also on the loading's character (static or dynamic loading) (Bal and Bektaş 2012). In general, wood can resist static loading to a greater extent than dynamic loading. Static loading is characterized by an increasing loading forc...
