• Journal of the Korean Wood Science and Technology
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• v.44 no.3
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• pp.295-301
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• 2016

In this study, relationship between seed origin and growth rate of Alnus glutinosa from different seed collection (Yugoslovia, ltaly, United Kingdom, Bulgaria) was investigated with focused on anatomical properties as wood fiber length, vessel element length and diameter. Alnus glutinosa showed diffuse-porous wood with scalariform perforation in alternate pitting. Ray height was 9~11 in tangential section and ray number were 16~26 in cross section. There were no differences on latewood focused on wood fiber length, length and diameter of vessel element, but difference on earlywood. Other than Yugoslavian seed, there was better growth rate with shorter wood fiber and vessel element length on latewood. However, seed from Yugoslovain showed better growth rate with longer wood fiber and vessel element length than other 3 seed orgins.

• Journal of the Korean Wood Science and Technology
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• v.23 no.3
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• pp.40-47
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• 1995

This study was carried out to develop a finite element analysis model that considers the semi-rigid characteristics of a wood-dowel joint, which is different from conventional joints that are used in the field of engineering. Wood-dowel joints are classified as semi-rigid joints that possess the following characteristics: (1) they are less stiffer than rigid joints and (2) their stiffness is determined by the dowel's diameter, depth of dowel embedment in the face member and quantity of pin dowels. In this study a finite element model that considers the changes in stiffness according to the above mentioned factors was developed and its suitability was verified by experiments using a wood-dowel joint test specimen made up of particleboards. After comparing the experimental results and the analysis results of the wood-dowel joint which was applied with the proposed finite element model, less than 10% of error was found which is considered to be negligibly small. Hence this shows that this proposed finite element model can be used to predict deformation of wood-dowel joints.

• Journal of the Korean Wood Science and Technology
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• v.22 no.3
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• pp.39-44
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• 1994

This study was carried out to investigate features pertaining to spiral thickenings, which was considered one of the most important diagnostic values, for wood identification. Species, kind of cells with spiral thickening, and ridge numbers of spiral thickening per axial mm were recorded in 71 families, 144 genera, 316 species of Korean hardwoods. Spiral thickening was observed in 128 of 316 species, about 40.5 % of all the investigated, and classified into 6 types on the basis of distributional patterns and morphological features as follows: 1. Type 1, present throughout all vessel element, which was found in 14 families, 19 genera, 43 species. 2. Type 2, present only in small vessel element, which was found in 18 families, 29 genera, 41 species. 3. Type 3, present both in small vessel element and wood fibers, which was found in 8 families, 17 genera, 29 species. 4. Type 4, present in wood fibers, which was found in 1 family, 1 genus, 1 species. 5. Type 5, present only in tail of vessel element, which was found in 4 families, 5 genera, 9 species. 6. Type 6, being present in vessel element faintly or partially, which was found in 2 families, 3 genera, 5 species.

• Journal of the Korean Wood Science and Technology
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• v.23 no.4
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• pp.46-53
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• 1995

The anatomy of Korean diffuse-porous woods, 36 families, 75 genera, 145 species, 215 specimens was described and analyzed. Sixteen wood anatomical characters, habit and phenology factors were determined by simple correlation and principal component analysis. Strong positive correlations were found between vessel element length and fiber length, ray width and ray height, simple pits of fiber wall and paratracheal parenchyma distribution. The results of principal component analysis (PCA) disclose the primitive characteristics and the direction of xylem evolution of Korean diffuse-porous woods. The xylem evolution scenario for Korean dicotyledonous woods is considered to be developed in the direction of decreasing trends of vessel frequency, vessel element length, and length/diameter(L/D) ratio of vessel element but increasing trends of vessel diameter, fiber length/vessel element length(F/V) ratio, libriform wood fibers, simple perforation, and homogeneous ray composition. Increase of vessel diameter and decrease of vessel frequency seem to be related to the improvement of conductive efficiency, and increase of the vessel element length and occurrence of scalariform perforation in vessel element may be related to enhanced of conductive safety. Also the libriform wood fibers and ray features appear to have relationship with mechanical support and nutrient metabolism, respectively.

• Journal of the Korean Wood Science and Technology
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• v.42 no.2
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• pp.138-146
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• 2014

Stem and root of Lindera erythrocarpa were described and compared in the wood anatomical aspects. Root wood appeared to differ from stem wood in the qualitative features of growth ring boundary, extraneous materials in vessel element and ray parenchyma cell, outline of ray, and sheath cell. In the quantitative features, there were differences between these two tissues in vessels per square millimeter, tangential diameter of vessel lumina, length of vessel element, and width of ray. These wood anatomical differences between stem above ground and root below ground were thought to be attributed to their different growth environments.

• Journal of the Korean Wood Science and Technology
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• v.23 no.2
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• pp.77-82
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• 1995

With the aim to utilize pine wood(Pinus densiflora Sieb. et Zucc.) as an interior building materials, such as flooring material, monoethylene glycol(MEG) resin solution was impregnated into greenwood. Specimens of three different qualities, that is, normal wood, resinous wood and compression wood, were prepared. Distribution of resin element(phosphorus) in MEG resin solution-impregnated woods and preservative effectiveness against brown rot fungi(Tyromyces palustris and Serpula lacrymans) of these woods were investigated. The results were as follows: 1. The concentration of phosphorus into cell walls of resinous wood and compression wood was lower compared to that of normal wood. This shows that the quality of wood has an influence on the penetration of MEG resin solution into the wood. It was shown from a leaching test that MEG resin could be leached out easily from the cell walls. 2. The resinous wood and compression wood, even without MEG resin solution impregnation had high decay resistance. For normal wood, significant improvement of preservative effectiveness was observed after impregnation of MEG resin solution. It was shown that MEG resin was leached out from the woods after leaching test, resulting in the reduction of preservative effectiveness. From this result, suitability of MEG resin solution-impregnated woods as an interior materials was recognized.

• Journal of the Korean Wood Science and Technology
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• v.43 no.4
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• pp.421-428
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• 2015

This study was carried out to investigate the relationship between anatomical characteristics and growth rate of Quercus rubra from different origins of seed. Anatomical characteristics showed that all Quercus rubra species were ring-porous woods with 1~3 layers of large pores in earlywood, but the latewood had small pores oriented in radial direction. There were slight differences in libriform fiber length and vessel element diameter in the earlywood among different provenance origins of seeds. In growth rate, the libriform fiber length and vessel element diameter was negative correlation in the earlywood, but not correlative in the latewood, and vessel element length was not correlative in the early and latewood, Volumetric composition of libriform fiber and ray in latewood was higher than those in ear lywood, and a higher composition of vessel element was observed in earlywood. Ray height was the range of from 11 to 15 cells.

• Composites Research
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• v.28 no.2
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• pp.58-64
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• 2015

The purpose of this paper is to suggest the effective equivalent finite element model for the impact limiter of a nuclear spent fuel shipping cask made of sandwich composite panels. The sandwich composite panels were composed of a metallic facesheet and a core material made of urethane foam, balsa wood and red wood, respectively. The effective equivalent finite element model for the impact limiter was proposed by comparing the results of low-velocity impact test of sandwich panels. An explicit finite element analysis based on LS-DYNA 3D was done in this study. The results showed that the solid elements were recommended to model the facesheet and core of sandwich panels for impact limiter compared to combination modeling method, in which the layered shell element for facesheet and solid element for core material are used. In particular, the solid element for balsa and red wood core materials should be modeled by the element elimination approach.

• Journal of the Korean Wood Science and Technology
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• v.26 no.1
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• pp.70-75
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• 1998

In this paper, the relationships between volumetric mixing ratio of rubber chip and physical and mechanical properties of wood/rubber composite panel was examined in order to investigate the mixture characteristics of wood and rubber chip. Because of the specific gravity of rubber differed from wood chip, physical properties of wood/rubber composite panel was shown very different values by mixing rate of chip element. Specific gravity in air-dry of composite panel was increased rapidly as volumetric percent of rubber chip was increased. Moisture content of composite panel was decreased as volumetric percent of rubber chip element was increased. This results was considered that wood weight is light and porosity material for moisture absorption. Compressive strength and modulus of rupture in bending test were decreased as volumetric percent of rubber chip increased. By mixing ratio control of chip elements, various wood/rubber composite panel can be applicable to every interior materials such as subfloor, playground, and exterior materials such as road blocks for recreational facilities in garden and forest and city parks.

• Journal of the Korean Wood Science and Technology
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• v.42 no.1
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• pp.20-26
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• 2014

This paper represented the finite element analysis to estimate structural performance of stress-laminated deck, which is determined by deflection, stress, and aging characteristics of tensioning. After loading, the deflected shape showed plate behavior because pre-stressing make frictional force between each member. Compared between initial post-tension and the results, pre-stressing forces were decreased with deck deflection. This is because deflection occurred in the deck so that pre-stressing decreased due to load reduction. However, material plasticity was not considered so that advanced researches should be performed.