scholarly journals PHYSICAL AND MECHANICAL PROPERTIES OF JUVENILE Schizolobium amazonicum WOOD

2018 ◽  
Vol 42 (1) ◽  
Author(s):  
Graziela Baptista Vidaurre ◽  
Benedito Rocha Vital ◽  
Angélica de Cássia Oliveira ◽  
José Tarcísio da Silva Oliveira ◽  
Jordão Cabral Moulin ◽  
...  

ABSTRACT Growth in world demand for wood implies a search for new fast growing species with silvicultural potential, and in this scenario for native species such as Paricá . Thus, the objective of this study was determining the physical and mechanical wood properties of the Schizolobium amazonicum species (known as Paricá in Brazil). Trees were collected from commercial plantations located in the north of Brazil with ages of 5, 7, 9 and 11 years. Four logs from trees of each age in the longitudinal direction of the trees were obtained, and later a diametrical plank of each log was taken to manufacture the specimens which were used to evaluate some physical and mechanical properties of the wood. The basic density of Paricá was reduced in the basetop direction and no difference between the radial positions was observed, while the average basic density of this wood was characterized as low. The region close to the bark showed less longitudinal contraction and also greater homogeneity of this property along the trunk, while for tangential contraction the smallest variation was found in the region near the pith. Paricá wood contraction was characterized as low. Age influenced most of the mechanical properties, where logs from the base had the highest values of mechanical strength.

Holzforschung ◽  
2020 ◽  
Vol 74 (12) ◽  
pp. 1089-1097
Author(s):  
José Clailson Franco Coelho ◽  
Graziela Baptista Vidaurre ◽  
João Gabriel Missia da Silva ◽  
Maria Naruna Felix de Almeida ◽  
Ramon Ferreira Oliveira ◽  
...  

AbstractThe relationship between grain angle and wood properties has not been focus of researches in wood industry. The aim of this study was to establish grain angle variations in commercial Eucalyptus logs and their effects on physical-mechanical wood properties. Wood maximum angular deviation (MAD) was correlated with density, volumetric shrinkage, compressive strength parallel to grain, flexural strength and stiffness as determined by bending and acoustic methods in wood of seven Eucalyptus grandis × Eucalyptus urophylla clones at 13 years old. The relationship between MAD at pith-bark and base-top positions and its effect on the physical and mechanical properties were evaluated. Amplitude of MAD values was small for the seven clones, and the mean was 6.2°. The grain deviation decreased by only 8% in base-top direction, and the correlations among MAD and three logs heights were small and negative (r = −0.13). MAD values presented an increasing trend of 33% in pith-bark direction, with a small positive correlation (r = 0.42). Basic density (BD) presented a significant correlation with the MAD (r = 26). There was no significant correlation between the MAD and volumetric shrinkage, mechanical properties and modulus of elasticity dynamic (determined by stress wave timer, ultrasound or transverse vibration).


2016 ◽  
Vol 36 (86) ◽  
pp. 135 ◽  
Author(s):  
Jussan Albarello de Cezaro ◽  
Rômulo Trevisan ◽  
Rafaelo Balbinot

Esse estudo objetivou avaliar as propriedades físico-mecânicas da madeira de Chrysophyllum marginatum (Hook. e Arn.) Radlk. Foram utilizadas três árvores com 20,3 ± 6 cm de diâmetro. Por regressão, determinou-se a variação no sentido base-topo de retratibilidade, coeficiente anisotrópico, teor de umidade saturado e massa específica básica. Para caracterizar a flexão estática na primeira tora, nas condições úmida e seca ao ar, foi realizada análise de variância pelo teste de Tukey. Observou-se decréscimo das contrações radial e tangencial e da massa específica básica da madeira no sentido base-topo, inversamente ao teor de umidade saturado, que apresentou uma variação crescente. Na análise do coeficiente anisotrópico, verificou-se uma tendência de acréscimo até 1,30 m de altura, seguido de estabilização a partir dessa posição até o topo. A contração longitudinal apresentou tendência de decréscimo até, aproximadamente, 40% de altura, seguido de acréscimo até a altura de inserção do primeiro galho vivo. As médias do coeficiente anisotrópico e da massa específica básica foram 2,3 kg m-3 e 594 kg m-3, respectivamente. A condição de umidade seca ao ar apresentou maior resistência à flexão estática do que quando saturada e os valores dos módulos de elasticidade e de ruptura foram semelhantes aos encontrados em estudos de Eucalyptus saligna e Carya illinoinensis.Physical and mechanical properties of Chrysophyllum marginatum woodThis study aimed to evaluate the physical and mechanical properties of the wood of Chrysophyllum marginatum (Hook. And Arn.) Radlk. We used three trees with 20.3 ± 6 cm of diameter. It was determined by regression analysis the variation bottom-up of shrinkage, anisotropic coefficient, saturate moisture content and basic density. To characterize the static bending in the first log, in saturate and air dried conditions, it was performed variance analysis using Tukey›s test. It was observed a decrease in radial and tangential contractions and basic density on bottom-up direction. Saturate moisture content increased, considering the same direction. Anisotropic coefficient presented increase tendency up to 1.30 m height followed by stabilization from that position to the top. It was observed decreasing tendency of longitudinal contraction to approximately 40% of total height, followed by increasing up to the insertion of the first living branch. Mean anisotropic coefficient and basic density were 2.3kg m-³ and 594 kg m-³, respectively. Air dry condition showed greater static bending resistance than when saturate. Values of rupture and elasticity modulus were similar to those found in studies with Eucalyptus saligna and Carya illinoinensis.Index terms: Shrinkage; Anisotropic coefficient; Static bending


2021 ◽  
Vol 10 (11) ◽  
pp. e421101119746
Author(s):  
Pedro Augusto Fonseca Lima ◽  
Cassiano Pacheco da Silva ◽  
Fernando Nunes Gouveia ◽  
Gabriela Bertoni Belini ◽  
Elias Ricardo Durango Padilla ◽  
...  

The use of Chromated Copper Borate (CCB) for wood treatment is known with several studies on a laboratory scale. However, there is a lack of field studies to analyze the effect of the CCB over time. This study aimed to evaluate the wood properties of Eucalyptus urophylla S.T. Blake x Eucalyptus grandis W. Mill ex Maiden (called E. urograndis), treated with CCB as well evaluate the leaching of chromium, copper and bore (Cr/Cu/B) in field test. The field experiment, with wood treated and untreated (no CCB application), was installed in 2016 and remained until 2018. Wood physico-mechanical properties were evaluated for each condition (treated and untreated) and at three different time: at 0, 1 and 2 years of field exposure. The elements (Cr/Cu/B) losses (leaching) were determined by the difference in the quantification of each element retained in the wood (retention), from year 0 (amount of original elements) in relation to years 1 and 2 of field exposure. The preservative treatment of E. urograndis wood with CCB was efficient to maintain its physical and mechanical properties (mass loss, basic density, rupture and elasticity modulus) during the 2 years of field exposure. The E. urograndis wood without CCB treatment showed reductions in the physical-mechanical properties, indicating their low natural durability. High leaching (close to 100%) for boron was observed. In addition, the total of CCB retention has not changed (statistically) after 2 years.


IAWA Journal ◽  
2014 ◽  
Vol 35 (2) ◽  
pp. 158-169 ◽  
Author(s):  
Zhao Rongjun ◽  
Yao Chunli ◽  
Cheng Xianbao ◽  
Lu Jianxiong ◽  
Fei Benhua ◽  
...  

The anatomical characteristics, chemical composition, and physical and mechanical properties of fast-growing Populus × euramericana cv. ‘74/76’ juvenile wood were investigated. Four- to five-year-old clonal plantation trees were harvested from two different experimental sites in the suburbs of Beijing. The Shunyi site had black alkali soil with a planting density of 4 × 6 m and the Miyun site had sandy loam soil with a planting density of 3 × 5 m. The test results showed that the poplar trees from the two sites were both fast growing, with poplar at Shunyi growing faster than at Miyun. There were no significant differences in wood properties between trees grown at the two sites. Fiber length at breast height varied from 872 to 1300 μm between growth rings, average fiber width varied from 21.0 to 25.5 μm and double wall thickness varied from 5.0 to 6.6 μm. Average cellulose, lignin and hemicellulose contents in the samples were 48.9%, 25.4%, and 18.8%, respectively. MFA was higher in the first two growth rings (20–25°), and then decreased rapidly to 12° close to the bark. The average air-dry density at breast height was 401 kg/m3 while the average MOE at breast height was 9.3 GPa. The trees showed large growth rates in both height and stem diameter during the growing season. However, wood properties of the juvenile poplar appeared to be similar to those of poplars with a slower growth rate.


2017 ◽  
Vol 52 (1) ◽  
pp. 49-52
Author(s):  
Elias ◽  
AK Das ◽  
MM Rahman ◽  
MA Islam

This research intends to explore the mechanical and physical properties of waterlogged rain tree (Samanea saman). The variation of mechanical and physical wood properties grown in waterlogged and non-waterlogged area were studied. Four trees of the species were selected from two areas. Important mechanical and physical properties were examined for the wood of two types of trees Oven dry density for the wood of waterlogged tree was 420 kg/m3 whether it was 550 kg/m3 for the wood of non-waterlogged tree. The MOR of wood of waterlogged tree was 58.2 N/mm2 and wood of non-waterlogged tree produced 78.1 N/mm2. The MOE of the wood of waterlogged tree and non-waterlogged tree were 1478 and 4876 N/mm2. The physical and mechanical properties were lower for the wood of waterlogged tree. Such findings may in proper uses of the species.Bangladesh J. Sci. Ind. Res. 52(1), 49-52, 2017


2014 ◽  
Vol 64 (1-2) ◽  
pp. 48-54 ◽  
Author(s):  
Wiwin Tyas Istikowati ◽  
Futoshi Ishiguri ◽  
Haruna Aiso ◽  
Fanny Hidayati ◽  
Jun Tanabe ◽  
...  

2018 ◽  
Vol 42 (2) ◽  
Author(s):  
Antonio José Vinha Zanuncio ◽  
Amélia Guimarães Carvalho ◽  
Angélica de Cassia Oliveira Carneiro ◽  
Mario Tomazello Filho ◽  
Paulina Valenzuela ◽  
...  

ABSTRACT Eucalyptus wood from adult trees is used for several purposes; however, the wood of younger trees has limited use. This study aims to characterize and propose uses of two-year-old eucalyptus wood. Six two-year-old Eucalyptus grandis × Eucalyptus urophylla clones have been selected and their anatomical, ultrastructural, physical and mechanical wood characteristics evaluated. The wood of Clone A shows more robust fibers with better microfibril arrangement, resulting in better mechanical properties, and therefore, a better performance for structural use. Clone F showed a low variation of wood basic density in the radial direction, facilitating its machinability, and with the Clone B, showed a lower anisotropy, and therefore, the wood is recommended for locations with high variations of humidity. The heterogeneity of the wood characteristics of the evaluated clones confirms the need for further studies, to choose those most adequate to each use.


Holzforschung ◽  
2016 ◽  
Vol 70 (6) ◽  
pp. 557-565 ◽  
Author(s):  
Marjan Sedighi Gilani ◽  
Jürg Neuenschwander ◽  
Markus Heeb ◽  
Roman Furrer ◽  
Sergio J. Sanabria ◽  
...  

Abstract The goal of the current study was to investigate the physical and mechanical properties of mycowood as a high quality tone-wood, obtained from Norway spruce by treatment of the white rot fungus Physisporinus vitreus as a function of the treatment time. In focus was the stiffness to weight ratio, which is often considered a main criterion for tone-wood selection. The vibro-mechanical properties were tested by non-destructive methods. The change of color and density were also measured after 4–12 months of fungal incubation. Density decreased up to 5% after 12 months of fungal treatment. Sound velocity was measured in small size specimens by means of the free-free vibration approach, while in large specimens the air-coupled ultrasound method was applied. The two techniques gave similar results and indicated that the sound velocity decreased in mycowood. Internal damping was increased in mycowood to a higher extent than the reduction in the specific modulus of elasticity (E/ρ) and thus the sound velocity in the material. The sound velocity was decreasing with increasing incubation times and scattering of data with this regard was larger in the transversal than in the longitudinal direction. The sound radiation coefficient and the characteristic impedance were enhanced in mycowood and its color was more brownish and richer in tone.


BioResources ◽  
2021 ◽  
Vol 16 (4) ◽  
pp. 6921-6932
Author(s):  
Tomislav Sinković ◽  
Branimir Jambreković ◽  
Tomislav Sedlar

The interpretation and presentation of research on the physical and mechanical properties of wood in the radial direction is important for the estimation of technological properties in primary wood processing. It is common practice to define the boundary between the juvenile and mature wood zone of tree growth because of the differences in wood properties in these two zones. The juvenile and mature wood zones can be determined statistically based on the significance of the difference in the properties in a particular zone. This paper presents the insufficiency in the statistical determination of the boundary between juvenile and adult wood. Such limitations detract from the potential value and technological exploitation of wood as raw material. Statistical tests yielded zones that were too wide for the transition of juvenile wood to mature wood. Representations of the distribution of properties in the radial direction also complement the knowledge for assessing the technological properties based on the researched use of the presentation of polynomials of the second degree and the display of the Tukey HSD test in the form of comparison tables. The graphical representations by groups of the tested annual rings of fir wood also help to assess the technological properties.


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