Eucalyptus nitens: nanomechanical properties of bark and wood fibers (original) (raw)
Related papers
Polymers
Plantation-grown Eucalyptus nitens (E. nitens) has been grown predominantly for the pulp and paper industry. In this study, the suitability of E. nitens as a structural material is examined using static tensile tests in a universal testing machine. The anisotropic tensile behaviour of 240 Eucalyptus nitens small clear wood samples with a diversity of grain angles was examined in both dry and wet conditions. The samples had a highly anisotropic tensile characterisation in the context of both a low moisture content (MC = 12%) and a high moisture content (MC > its fibre saturation point, FSP). The results showed that, in a high moisture content condition, the wood showed a lower failure strength and more ductility at all grain angles than in a low moisture content condition. The underlying failure mechanism of Eucalyptusnitens timber in tension was determined in detail from the perspective of the microstructure of wood cellulose polymer composites. The mean tensile failure strengths...
Wood Utilization of Eucalyptus grandis in Structural Elements: Densities and Mechanical Properties
Engenharia AgrÃcola, 2018
Over the years, the species of eucalyptus has become a multipurpose raw material. In addition, the most relevant aspect of the use for various purposes is related to the production of a high quality wood, coming from short duration plantations, which is fundamental to the current demand of the industries. However, its use in civil construction has not yet reached a level of importance, due to the low knowledge of many of its resistance properties and the consequent popular fear in the use of reforestation woods, in particular the Eucalyptus grandis. This research investigated its main mechanical properties, aiming to reinforce its constructive applications in wood structures. For this, two physical properties and fourteen mechanical properties, in two different moisture conditions of the samples were evaluated, according to the norm NBR 7190 (1997). In the first moisture content, the samples were stabilized at 30%, while the second level considered the content of 12%. It was obtained 3580 determinations for the sixteen properties. From the 14 mechanical properties, only 7 had significant increases with the moisture reduction (30% to 12%), consisting of the rupture modulus in the parallel and normal compressions, normal traction and static bending; modulus of elasticity in normal compression and static bending and in shear strength.
Microstructure Description and Micromechanical Properties of Spruce Wood
Acta Polytechnica, 2015
The knowledge about the microstructure and morphology of individual phases also allows an artificial modification of the material, or its processing, to produce engineered products with required properties. The purpose of our work was to investigate the distribution of elastic stiffness within the tissues of individual cells using the finest equipment and to observe the morphology of individual phases. A quasi-static nanoindentation was carried out on the cell walls of earlywood and latewood tracheids of spruce wood. The dynamic modulus mapping, also known as nanoDMA, was utilized to obtain the map of elastic moduli over the entire tracheid cross-section. In particular, it was found that the stiffness cells walls is approximately 10.5 GPa and 12.5 GPa in the case of earlywood and latewood tracheids, respectively. The difference between earlywood and latewood elastic stiffness is attributed to a different chemical composition and orientation of fibrils. The acquired data are indispen...
Engineering Wood Products from Eucalyptus spp
Advances in Materials Science and Engineering, 2022
Forest covers 4.06 billion hectares (ha) or 31% of the total land area worldwide, where 93% (3.75 billion ha) are natural regenerating forests and the remaining 7% (294 million ha) are planted forests. Eucalyptus spp., being one of the most important plantation species, has been planted in 95 countries around the world, and the area of plantation has exceeded 22.57 million ha. In the southern hemisphere, it is a significant industrial fast-growing tree species. These plantations serve as a valuable resource for the timber and fibre-based industries. Eucalyptus is the main fibre resource for the pulp and paper industries in developed countries. Timber extracted from the planted eucalyptus trees has long been used for solid wood and its fibres were used for manufacturing medium-density fibreboard. In comparison to most softwood species, Eucalyptus timber is reported to have a higher rigidity, making it ideal for manufacturing structural products. Therefore, this paper presents a revie...