scholarly journals Effect of accelerated weathering test on selected properties of bamboo, Scots pine and Oriental beech wood treated with waterborne preservatives

2019 ◽  
Vol 70 (4) ◽  
pp. 391-398
Author(s):  
Elif Topaloglu
Keyword(s):  
Scots Pine ◽  
Compression Strength ◽  
Modulus Of Elasticity ◽  
Beech Wood ◽  
Mechanical Tests ◽  
Modulus Of Rupture ◽  
Accelerated Weathering ◽  
Oriental Beech ◽  
Static Modulus ◽  
The Difference

This paper investigates the changes in density, compression strength parallel to grain, static modulus of rupture and modulus of elasticity of untreated (control) and waterborne-treated bamboo (Phyllostachys bambusoides), Scots pine (Pinus sylvestris) and Oriental beech (Fagus orientalis) specimens subjected to accelerated weathering using an accelerated weathering chamber for 672 hours. Wolmanit-CB (CCB), tanalith-E (Tan-E), amine copper quat-1900 (ACQ) and boric acid-borax (BB) were used as waterborne preservatives. The retention value of bamboo specimens was lower than that of wood specimens due to the difference in anatomical structure of bamboo. The value of density, compression strength parallel to grain, static modulus of rupture and modulus of elasticity of treated bamboo and wood were generally higher than those of untreated specimens after accelerated weathering. ACQ treatment generally provided the best protection against weathering in all mechanical tests for both bamboo and wood specimens, while CCB treatment provided an effective protection against weathering in compression strength for Oriental beech. BB treatment provided the least protection against weathering for bamboo and wood specimens compared to other waterborne preservatives.

Nondestructive Evaluation of Red Oak and White Oak Species

2020 ◽  
Vol 70 (3) ◽  
pp. 370-377
Author(s):  
Cristian Grecca Turkot ◽  
Roy Daniel Seale ◽  
Edward D. Entsminger ◽  
Frederico José Nistal França ◽  
Rubin Shmulsky
Keyword(s):  
Modulus Of Elasticity ◽  
Longitudinal Vibration ◽  
Mechanical Tests ◽  
Modulus Of Rupture ◽  
Red Oak ◽  
Quercus Alba ◽  
White Oak ◽  
Static Modulus ◽  
Static Modulus Of Elasticity ◽  
The Relationship

Abstract The objective of this article is to evaluate the relationship between the dynamic modulus of elasticity (MOEd), which was obtained with acoustic-based nondestructive testing (NDT) methods, and static bending properties of two domestic hardwood oak species. The mechanical properties were conducted using static modulus of elasticity (MOE) and modulus of rupture (MOR) in radial and tangential directions. Mechanical tests were performed according to ASTM D143 on small clear, defect-free specimens from the two tree species: red oak (Quercus rubra) and white oak (Quercus alba). The MOEd was determined by two NDT methods and three longitudinal vibration methods based on the fast Fourier transform. The destructive strength values obtained in this study were within the expected range for these species. The MOE was best predicted by NDT methods for both species but also had a strong capability to predict MOR.

Medium Density Particleboard with Addition of Impregnated Paper

2014 ◽  
Vol 1025-1026 ◽  
pp. 543-546
Author(s):  
Juliana Cortez Barbosa ◽  
Anderson Luiz da Silva Michelon ◽  
Elen Aparecida Martines Morales ◽  
Cristiane Inácio de Campos ◽  
André Luis Christoforo ◽  
...  
Keyword(s):  
Moisture Content ◽  
Modulus Of Elasticity ◽  
Mechanical Tests ◽  
Modulus Of Rupture ◽  
Medium Density ◽  
Test Results ◽  
Thickness Swelling ◽  
Adhesion Test ◽  
Layer Medium ◽  
Determine Moisture Content

The aim of this research was to produce three-layer Medium Density Particleboard (MDP), with the addition of impregnated paper, in the inner layer, in proportions of 1; 5 and 20%. In this study, MDP was composed with particles of small size in outer layers, and larger particles in internal layer. After panel manufacturing, physical and mechanical tests based on Brazilian Code ABNT NBR 14.810 were carried out to determine moisture content; density; thickness swelling; water absorption; modulus of rupture (MOR) and modulus of elasticity (MOE) in static bending and internal adhesion. Test results were compared to commercial panels, produced with 100% Eucalyptus, considering the requirements specified by Brazilian Code. Properties presented values close to normative specifications, indicating positively the possibility of production of MDP using addition of waste paper impregnated.

scholarly journals Dynamic and static comparison of beech wood dovetail, tongue and groove, halving, and dowel joints

BioResources ◽  
2020 ◽  
Vol 15 (2) ◽  
pp. 3787-3798
Author(s):  
Amir Mollahassani ◽  
AmirHooman Hemmasi ◽  
Habibollah Khademi Eslam ◽  
Amir Lashgari ◽  
Behzad Bazyar
Keyword(s):  
Modulus Of Elasticity ◽  
Pearson Correlation ◽  
Dynamic Assessment ◽  
Beech Wood ◽  
Static Tests ◽  
Static Modulus ◽  
Fagus Orientalis Lipsky ◽  
Significant Difference ◽  
The Mean ◽  
Static Modulus Of Elasticity

Dynamic and static elastic properties beech wood joints were assessed. Conventional joints, namely dovetail, tongue and groove, dowel, and halving joints were prepared with beech wood (Fagus orientalis Lipsky) using polyvinyl acetate and cyanoacrylate adhesives. The results of the dynamic and static modulus of elasticity of the joints in this research indicated the highest reduction trends in halving, dowel, tongue and groove, and dovetail joints, respectively. The modulus of dovetail joint elasticity, its homogeneous joint texture, and lack of an extended adhesive line, corresponded to that of the jointed samples. The average static modulus of elasticity was approximately 10.5% lower than that of the dynamic modulus of elasticity. The results of the Student’s t-test indicated a significant difference between the mean of dynamic and the mean of static modulus of elasticity, significance at 5% level and the Pearson correlation test indicated that the dynamic and static modulus of elasticity of the samples were significant at the 5% level and indicated a positive correlation. Based on the observed correlation in the dynamic and static tests’ results, using these methods, dynamic assessment of NDTs may be regarded as an appropriate alternative in standardizing destructive static testing for wood assessment and categorization.

scholarly journals Physical and Mechanical Properties Evaluation of Corncob and Sawdust Cement Bonded Ceiling Boards

2019 ◽  
Vol 42 ◽  
pp. 65-75 ◽  
Author(s):  
Atoyebi Olumoyewa Dotun ◽  
Odeyemi Samson Olalekan ◽  
Azeez Lateef Olugbenga ◽  
Modupe Abayomi Emmanuel
Keyword(s):  
Mechanical Properties ◽  
Modulus Of Elasticity ◽  
Cement Content ◽  
Physical And Mechanical Properties ◽  
American National Standard Institute ◽  
Mechanical Tests ◽  
Industrial Wastes ◽  
Modulus Of Rupture ◽  
National Standard ◽  
Thickness Swelling

This study considered the production of composite ceiling boards from both agricultural and industrial wastes. Boards with different blending proportions by weight of cement, corncob and sawdust (Cem:Ccb:Swd) were produced and tested. Physical and mechanical tests such as Water Absorption (WA), Thickness Swelling (TS), Modulus of Elasticity (MOE) and Modulus of Rupture (MOR) were carried out on the products. The findings revealed that the board with Cem:Ccb:Swd blending proportion 50:10:40 gave the highest values of MOE and MOR and also had the lowest values of WA and TS. The MOE and MOR values of 3.432 are both higher than the minimum values of 550 N/mm2 and 3 N/mm2 specified for MOE and MOR respectively by the American National Standard Institute, for general-use particle boards. The cement content is inversely proportional to the physical properties and directly proportional to the mechanical properties.

scholarly journals Prediction of Mechanical Properties of Hardwood Species Using the Longitudinal Vibration Acoustic Method

2021 ◽  
Vol 71 (4) ◽  
pp. 391-400
Author(s):  
Kayode Olaoye ◽  
Lawrence Aguda ◽  
Bolade Ogunleye
Keyword(s):  
Mechanical Properties ◽  
Modulus Of Elasticity ◽  
Dynamic Modulus ◽  
Longitudinal Vibration ◽  
Modulus Of Rupture ◽  
Damping Factor ◽  
Acoustic Parameters ◽  
Static Modulus ◽  
Hardwood Species ◽  
Static Modulus Of Elasticity

Abstract Acoustic test methods such as longitudinal vibration have been developed to predict the elastic properties of wood. However, attention has not been shifted to using this method to predict other mechanical properties, especially on Nigeria's preferred, and lesser-used wood species. Thus, we further investigate relationships among mechanical and acoustic properties of selected hardwood species with a view of predicting the mechanical properties of wood from acoustic parameters. Clear wood samples (324) of 20 by 20 by 20 mm3 were collected axially from Albizia adianthifolia, Gmelina arborea, Delonix regia, and Boscia anguistifolia trees, and conditioned before testing. The longitudinal vibration method was adopted to test for the dynamic (acoustic) parameters and properties (fundamental frequency, damping factor, dynamic modulus of elasticity, sound velocity, specific elastic modulus, radiation coefficient, acoustic conversion efficiency, acoustic impedance) while the universal testing machine was used to test for the mechanical properties (static modulus of elasticity, modulus of rupture, maximum compression strength parallel to grain). The damping factor, dynamic modulus of elasticity, and acoustic impedance were the best acoustic parameters that significantly correlated with the static modulus of elasticity (−0.57, 0.81, 0.76), modulus of rupture −0.64, 0.82, 0.85) and maximum compression strength parallel to grain (−0.52, 0.78, 0.84), respectively. There was a significant difference in the mechanical properties with respect to species, thus A. adianthifolia and G. arborea were mechanically better than D. regia and B. anguistifolia for construction or structural purposes. This study revealed that additional new acoustic measures are suitable for inferring mechanical wood properties.

Mechanical properties of oriented bamboo scrimber boards made of Phyllostachys pubescens (moso bamboo) from Taiwan and China as a function of density

Holzforschung ◽  
2018 ◽  
Vol 72 (2) ◽  
pp. 151-158 ◽  
Author(s):  
Min-Jay Chung ◽  
Sheng-Yang Wang
Keyword(s):  
Density Distribution ◽  
Dimensional Stability ◽  
Modulus Of Elasticity ◽  
Strength Properties ◽  
Moso Bamboo ◽  
Modulus Of Rupture ◽  
Fiber Direction ◽  
Phyllostachys Pubescens ◽  
Static Modulus ◽  
Bamboo Scrimber

AbstractThe properties of oriented bamboo scrimber boards (OBSB) have been investigated at three density levels (0.8, 0.9, and 1.0 g cm3), while the boards were made from moso bamboo (Phyllostachys pubescens) grown in Taiwan (T-OBSB) and China (C-OBSB). A non-destructive technique (NDT), ultrasonic-wave velocity (Vu) measurements were applied and the dynamic modulus of elasticity (MOEdyn) was calculated. Moreover, static modulus of elasticity (MOE), modulus of rupture (MOR), profile density distribution, internal bond strength (IB), springback (SB), and dimensional stability were determined based on traditional methods. Positive linear relationships between density andVu, MOEdyn, MOE and MOR were observed, no matter if the measurements were done parallel (//) or perpendicular (⊥) to the fiber direction of the OBSBs. Moreover,Vu(//), MOEdyn,u(//), MOE(//), and MOR(//)were higher thanVu(⊥), MOEdyn,u(⊥), MOE(⊥)and MOR(⊥). C-OBSB had slightly lowerVu(//),Vu(⊥), MOEdyn,u(//)and DMOEu(⊥)values than T-OBSB. T-OBSB had higher MOE(//), MOE(⊥)and MOR(//)than C-OBSB, but less MOR(⊥). The profile density distribution of high-density T-OBSB showed singnificant data scattering. The profile density distribution of C-OBSB was homogeneous at all density levels. IB and SB data are directly proportional to density, but water absorption, thickness swelling and volumetric swelling are inversely proportional to density. T-OBSB has better bonding and strength properties, and dimensional stability than C-OBSB.

scholarly journals AVALIAÇÃO DE TIPOS DE ONDAS GERADAS POR DOIS MODELOS DE TRANSDUTORES PARA DETERMINAÇÃO DO MÓDULO DE ELASTICIDADE DINÂMICO

FLORESTA ◽  
2010 ◽  
Vol 40 (4) ◽  
Author(s):  
Diego Martins Stangerlin ◽  
Joaquim Carlos Gonçalez ◽  
Raquel Gonçalves ◽  
Elio José Santini ◽  
Leandro Calegari ◽  
...  
Keyword(s):  
Surface Waves ◽  
Modulus Of Elasticity ◽  
Dynamic Modulus ◽  
Ultrasonic Method ◽  
Point Contact ◽  
Static Modulus ◽  
Dynamic Modulus Of Elasticity ◽  
Ultrasonic Equipment ◽  
The Difference ◽  
Static Modulus Of Elasticity

O objetivo deste estudo foi de avaliar os tipos de ondas gerados por dois modelos de transdutores utilizados para determinação do módulo de elasticidade dinâmico por meio de ensaios com ultrassom e correlacioná-los ao módulo de elasticidade estático obtido por compressão paralela às fibras. Para tanto, utilizou-se um aparelho de ultrassom dotado de transdutores faces planas e de pontos secos com freqüência de 50 kHz. A velocidade ultra-sônica foi determinada ao considerar a transmissão da onda ao longo do comprimento de amostras de madeira com dimensões nominais de 5 x 5 x 20 cm. Para avaliar a sensibilidade do método ultra-sonoro e os tipos de ondas gerados pelos respectivos transdutores, as amostras foram ensaiadas destrutivamente à compressão paralela, com determinação do módulo de elasticidade por ambas metodologias. Apesar da diferença de valores absolutos do módulo de elasticidade entre os ensaios de ultrassom com transdutores faces planas, que geraram ondas longitudinais, e os ensaios de compressão paralela, em função da natureza viscoelástica da madeira, verificou-se uma boa correlação entre os dados. Com relação ao uso dos transdutores pontos secos, que geraram ondas de superfície, não foi verificada boa correlação com os ensaios destrutivos.Palavras-chave:  Ondas longitudinais; ondas de superfície; transdutores de faces planas; transdutores de pontos secos; ensaios não-destrutivos. AbstractEvaluation of wavess generated for two models of transducers for determining the dynamic modulus of elasticity. This study aimed to evaluate the types of waves generated for two transducers used for determining the dynamic modulus of elasticity by tests with ultrasound and to correlate them to the static modulus of elasticity obtained by parallel compression. For this study ultrasonic equipment with planes faces and point-contact transducers of 50 kHz was used. The ultrasonic speed was determined considering the transmission of the wave along the length of the samples with nominal dimensions of 5 x 5 x 20 cm. To evaluate the sensitivity of the ultrasonic method and the types of waves generated for the transducers, samples were submitted to destructive conventional parallel compression, with determination of the elasticity modulus for both methodologies. Although the difference of absolute values between tests of ultrasound with transducers planes faces, that generated longitudinal waves, and parallel compression, due to wood viscoelastic nature, there was a good correlation between the obtained data. It was not observed good correlation between the use of point-contact transducers, which generated surface waves, and the destructive tests.Keywords:Longitudinal waves; surface waves; planes faces transducers; point-contact transducers; not-destructive methods.

scholarly journals Effects of modification with glutaraldehyde on the mechanical properties of wood

Holzforschung ◽  
2010 ◽  
Vol 64 (4) ◽  
Author(s):  
Zefang Xiao ◽  
Yanjun Xie ◽  
Holger Militz ◽  
Carsten Mai
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Scots Pine ◽  
Compression Strength ◽  
Bending Strength ◽  
Weight Percent Gain ◽  
Strength Loss ◽  
Modulus Of Rupture ◽  
Finite Span ◽  
Decreasing Ph

Abstract Scots pine (Pinus sylvestris L.) sapwood was treated with glutaraldehyde (GA) and magnesium chloride (MgCl2) as a catalyst. The effects of treating conditions on the mechanical properties were examined. The weight percent gain (WPG) of thin veneer strips after leaching was highest at pH 4.0–4.5 and tensile strength measured in zero-span strength and finite-span strength decreased with decreasing pH in a range of 3.5–5.5. Sole treatment with MgCl2 also gradually decreased the tensile strength up to 25% with decreasing pH. At a fixed GA concentration (1.2 M), increasing MgCl2 concentration linearly diminished tensile strength. Conversely, increasing GA at a fixed MgCl2 concentration (1.5%) displayed the same effect, whereas in both cases zero-span strength loss was higher than finite span-strength loss. GA treatment of Scots pine sapwood stakes did not affect the modulus of rupture and the modulus of elasticity, but significantly reduced work to maximum load in bending and impact bending strength indicating embrittlement of wood. At the same time, compression strength increased with increasing WPG of GA. It is assumed that embrittlement caused by hydrolysis and crosslinking of cell wall polymers is compensated by enhanced compression strength thereby resulting in unchanged bending strength.

scholarly journals Wood Quality Characterization of Sycamore Maple (Acer pseudoplatanus L.) and its Utilization in Wood Products Industries

2021 ◽  
Vol 42 (3) ◽  
Author(s):  
Tomislav Sedlar ◽  
Bogoslav Šefc ◽  
Srđan Stojnić ◽  
Tomislav Sinković
Keyword(s):  
Mechanical Properties ◽  
Compression Strength ◽  
Modulus Of Elasticity ◽  
Bending Strength ◽  
Wood Quality ◽  
Beech Wood ◽  
Wood Products ◽  
Dry Density ◽  
Acer Pseudoplatanus ◽  
Sycamore Maple

This study quantified the physical and mechanical properties of sycamore maple (Acer pseudoplatanus L.) as a basis for assessing wood quality. The physical properties of oven-dry density, density at 12% MC, green density, basic density, longitudinal, radial, tangential and volumetric shrinkages were tested and the mechanical properties of bending strength, modulus of elasticity at bending, compression strength parallel to grain and compression strength in radial and tangential direction as well as of Brinell hardness on the cross, radial, and tangential section were determined. Five sycamore maple trees from Medvednica region were selected for the purposes of this research. The results were compared with known literature data on sycamore maple wood, beech wood from the same sight, and beech wood from Gorski Kotar region. For a better understanding of sycamore maple physiology, as well as for assessing the quality of wood products, the distribution of wood properties within the tree radius, from pith to bark, was investigated. There was a general bell shaped distribution, in the radial direction, in wood density, and mechanical properties of sycamore maple wood. Shrinkages decreased from pith to bark, except for tangential shrinkage with bell shaped pattern. All investigated wood densities of sycamore maple from Medvednica were similar to the findings of studies known in literature, as well as shrinkages, except for the lower longitudinal shrinkage. Investigated mechanical properties of sycamore maple wood were similar to the findings of studies known in literature, except for the lower bending strength and modulus of elasticity (MOE). Investigated sycamore maple indicated better dimensional stability than beech wood from two locations in the region, although it did not match the beech wood regarding mechanical properties, especially wood hardness.

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