scholarly journals Studi Mutu Kayu Jati di Hutan Rakyat Gunungkidul IV. Sifat Mekanika Kayu

2016 ◽  
Vol 9 (2) ◽  
pp. 117
Author(s):  
Sri Nugroho Marsoem ◽  
Vendy Eko Prasetyo ◽  
Joko Sulistyo ◽  
Sudaryono ◽  
Ganis Lukmandaru
Keyword(s):  
Mechanical Properties ◽  
Shear Strength ◽  
Bending Strength ◽  
Wood Quality ◽  
Basic Density ◽  
Tectona Grandis ◽  
Modulus Of Rupture ◽  
Maximum Compression ◽  
Site Factor ◽  
Community Forests

Sifat mekanika dari kayu gergajian adalah persyaratan terpenting dalam banyak penerapan khususnya untuk keperluan konstruksi. Paper ini merupakan lanjutan dari penelitian sifat fisika kayu di tiga tempat tumbuh (Panggang, Playen, Nglipar) hutan rakyat Kabupaten Gunungkidul. Pengujian sifat mekanika dilakukan mengacu pada British Standards 373:57. Hasil penelitian menunjukkan bahwa kayu yang diteliti termasuk dalam kelas kuat II-III. Dari perhitungan analisis varian, tempat tumbuh berpengaruh nyata pada modulus patah (MoR) keteguhan lengkung statik, keteguhan tekan tegak lurus serat maksimum, keteguhan geser, dan kekerasan. Secara keseluruhan, kecuali untuk nilai MoR, sampel kayu dari Nglipar memberikan nilai kekuatan yang lebih tinggi. Pengaruh arah aksial dan radial pohon secara umum tidak begitu terlihat pada semua parameter kekuatan kecuali di keteguhan belah. Meskipun berkorelasi secara linier, hanya korelasi moderat yang diamati dari hubungan sifat mekanika (MoR/keteguhan geser) dan kerapatan dasar. Tidak ada korelasi nyata antara kerapatan dasar dan modulus elastisitas keteguhan lengkung statik serta antara kerapatan dasar dan keteguhan tekan sejajar serat maksimum.Kata kunci: Tectona grandis, sifat mekanika, kerapatan dasar, hutan rakyat, Gunungkidul. A study of teak wood quality from community forests in Gunungkidul  IV. Mechanical PropertiesAbstractMechanical properties of sawn timber are the most important characteristics in many applications, particularly for structural timber. The previous paper in this series reported on the physical properties of teak trees at different sites (Panggang, Playen, Nglipar) from community forests in Gunungkidul regency. In this study, the mechanical properties were evaluated according to British Standards 373:57. The results showed that the timber were classified in the II-III of strength class. By analysis of variance, site factor affected the values of modulus of rupture (MoR) in statical bending strength, maximum compression perpendicular to grain strength, shear strength and hardness. In general, except for MoR, the wood samples from Nglipar gave higher strength levels. Except for cleavage strength, the effects of the axial and radial position of the tree on mechanical properties were mostly negligible. Although linearly related, only modest correlations were observed between the mechanical parameters (MoR/shear strength) and basic density. No significant correlation was found between the values of basic density and modulus of elasticity of static bending strength as well as between basic density and the strength of maximum compression parallel to grain.

Mechanical properties of Ficus vallis-choudae (Delile), a lesser utilized species in Nigeria

BioResources ◽  
2020 ◽  
Vol 15 (3) ◽  
pp. 6550-6560
Author(s):  
Lawrence Aguda ◽  
Babatunde Ajayi ◽  
Sylvester Areghan ◽  
Yetunde Olayiwola ◽  
Aina Kehinde ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Shear Strength ◽  
Moisture Content ◽  
Modulus Of Elasticity ◽  
Bending Strength ◽  
High Strength ◽  
Strength Properties ◽  
Modulus Of Rupture ◽  
Impact Bending ◽  
Timber Market

Declining availability of the prime economic species in the Nigerian timber market has led to the introduction of Lesser-Used Species (LUS) as alternatives. Their acceptability demands information on the technical properties of their wood. The aim of this study was to investigate the mechanical properties of Ficus vallis-choudae to determine its potential for timber. Three mature Ficus vallis-choudae trees were selected and harvested from a free forest area in Ibadan, Oyo State, Nigeria. Samples were collected from the base (10%), middle (50%), and top (90%) along the sampling heights of each tree, which was further partitioned into innerwood, centrewood, and outerwood across the sampling radial position. Investigations were carried out to determine the age, density, moisture content, impact strength, modulus of elasticity, modulus of rupture, compressive strength parallel-to-grain, and shear strength parallel-to-grain. The mean impact bending strength, modulus of rupture, modulus of elasticity, maximum shear strength parallel-to-grain, and maximum compression strength parallel-to-grain for Ficus vallis-choudae at 12% moisture content were 20.4 N/mm2, 85.8 N/mm2, 709 N/mm2, 10.7 N/mm2, and 33.6 N/mm2, respectively. The study found the species to be dense with high strength properties in comparison with well-known timbers used for constructional purposes.

scholarly journals Variations in Physico-Mechanical Properties of Lonchocarpus sericeus (Poir), a Lesser-Used Species in West Africa

2021 ◽  
Vol 71 (3) ◽  
pp. 252-261
Author(s):  
Lawrence Olanipekun Aguda ◽  
Babatola Olufemi ◽  
Babatunde Ajayi ◽  
Olajide Rasaq Adejoba ◽  
Adedeji Robert Ojo ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Shear Strength ◽  
Modulus Of Elasticity ◽  
Bending Strength ◽  
High Strength ◽  
Modulus Of Rupture ◽  
Wood Age ◽  
Lonchocarpus Sericeus ◽  
The Mean ◽  
End Use

Abstract This study investigates the properties of Lonchocarpus sericeus to determine its potential use for timber. Three matured trees of L. sericeus were selected from a forest located in Longe Village, Oluyole Local Government Area in Oyo State, Nigeria. Discs from the harvested trees were collected at the base (10%), middle (50%), and top (90%) and further partitioned into inner wood, center wood, and outer wood. An investigation was carried out to characterize the wood age, density, shrinkage, impact strength, modulus of elasticity, modulus of rupture, compressive, and shear strength. The ages were 28, 29 and 32 years. The mean wood density at 12 percent moisture content was 836.63 kg/m3, which shows that it belongs to the high-density wood category. The mean shrinkage values in the radial, tangential, and longitudinal directions were 2.50, 3.99, and 0.78 percent respectively; the volumetric shrinkage was 6.36 percent. These shrinkage values were indicative of good dimensional stability. The mean impact bending strength, modulus of rupture, modulus of elasticity, maximum shear strength parallel to grain, and maximum compression strength parallel to the grain were 24.14, 114.18, 11,276, 12.76, and 47.16 N/mm2, respectively. End-use assessments suggest that the wood species can be used in similar applications as well-known timbers. The study found L. sericeus to be very dense with high strength in comparison to well-known timbers. It was observed that the mechanical properties of the species decrease from the base to the top and also increase from the outer wood to the core wood.

Influence of Moisture Content in some Mechanical Properties of Two Brazilian Tropical Wood Species

2014 ◽  
Vol 1025-1026 ◽  
pp. 42-45 ◽  
Author(s):  
Luiz A. Melgaço N. Branco ◽  
Eduardo Chahud ◽  
André Luis Christoforo ◽  
Francisco Antonio Rocco Lahr ◽  
Rosane A.G. Battistelle ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Shear Strength ◽  
Moisture Content ◽  
Analysis Of Variance ◽  
Wood Species ◽  
Modulus Of Elasticity ◽  
Modulus Of Rupture ◽  
Tropical Wood ◽  
Fiber Saturation ◽  
Brazilian Standard

This study aimed, with the aid of analysis of variance (ANOVA), to investigate and quantify the influence of moisture ranging between 12% and over 30% (fiber saturation) on the mechanical properties: strength and modulus of elasticity in compression and in tension parallel to grain; modulus of rupture and modulus of elasticity in static bending; shear strength parallel to grain considering wood species Ipê (Tabebuia sp) and Angelim Araroba (Vataireopsis araroba). Tests were performed according to the assumptions and calculating methods Brazilian standard ABNT NBR 7190, Anexx B, totalizing 400 tests. Results of ANOVA revealed a significant reduction (16% on average) for mechanical properties wood due to the increase in moisture content from 12% to over 30% (fiber saturation). The same behavior also occurred when assembly containing the two species was considered.

How Variability in OSB Mechanical Properties Affects Biological Durability Testing

Holzforschung ◽  
2003 ◽  
Vol 57 (1) ◽  
pp. 8-12
Author(s):  
S. F. Curling ◽  
J. E. Winandy ◽  
C. Carll ◽  
J. A. Micales ◽  
A. A. Tenwolde
Keyword(s):  
Mechanical Properties ◽  
Bending Strength ◽  
Particle Orientation ◽  
Modulus Of Rupture ◽  
Simple Method ◽  
Oriented Strandboard ◽  
Two Samples ◽  
Durability Testing ◽  
Biological Durability ◽  
Tensile Surface

Summary Loss in bending strength of wood has been shown to be a more sensitive measure of decay than is weight loss. Using modulus of rupture as the decay criterion is problematic for oriented strandboard (OSB) because of variation in mechanical properties due to particle orientation and size. Moreover, the small specimen size required for such tests increases the variance in mechanical properties. This study compared the variance in bending strength of ASTM D1037 standard-sized specimens and small specimens from two samples of commercial OSB. The small specimens were found to have a significantly higher level of variance in bending strength than the standard-sized specimens. A simple method of sorting the specimens based on strand orientation on the tensile surface significantly reduced the level of variance measured. The effects of differing levels of variance on the size, design and limitations of the experimental study are presented.

scholarly journals Physical and mechanical properties of impregnated polystyrene jabon (Anthocephalus cadamba) glulam

2021 ◽  
Vol 891 (1) ◽  
pp. 012007
Author(s):  
Y S Hadi ◽  
E N Herliyana ◽  
I M Sulastiningsih ◽  
E Basri ◽  
R Pari ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Shear Strength ◽  
Moisture Content ◽  
Physical And Mechanical Properties ◽  
Solid Wood ◽  
Hot Water ◽  
The Other ◽  
Modulus Of Rupture ◽  
Glued Laminated Timber ◽  
Anthocephalus Cadamba

Abstract Jabon (Anthocephalus cadamba) laminas were impregnated with polystyrene and reached 21.2% polymer loading. The laminas were manufactured for three-layer glued laminated timber (glulam) using isocyanate glue with glue spread 280 g/m2 and cold-press process. For comparison purposes, untreated glulam as control and also solid wood were prepared. The physical-mechanical properties were evaluated according to the Japanese Agricultural Standard (JAS) 234-2003. The results showed that the color of glulam was not different from polystyrene glulam. The density of polystyrene glulam was higher than untreated glulam and solid wood, but the moisture content was lower than the other. The product kinds of solid wood, untreated glulam, and polystyrene glulam did not affect shear strength and modulus of rupture (MOR), while the modulus of elasticity (MOE) of untreated glulam and hardness of polystyrene glulam were the highest values and the other products were not different one each other. Both kinds of glulam fulfilled the Japanese standard in terms of moisture content, MOR, and delamination in hot water, but MOE and shear strength did not. Regarding its advantages, polystyrene glulam could be further developed using a higher wood density.

Effect of Needling Parameters on Mechanical Properties of C/C Composites Reinforced by Carbon Cloth

2007 ◽  
Vol 546-549 ◽  
pp. 1521-1524
Author(s):  
Xiao Hu Zhang ◽  
He Jun Li ◽  
Zhi Biao Hao ◽  
Hong Cui
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Shear Strength ◽  
Compression Strength ◽  
Bending Strength ◽  
Interlaminar Shear Strength ◽  
Carbon Cloth ◽  
Depth Range ◽  
Needle Punching ◽  
Interlaminar Shear

The influence of needling parameters on mechanical properties of carbon-carbon (C-C)composites reinforced by needled carbon cloth was studied in the present investigation. The results showed that needling density (ND)and needle-punching depth (PD) both had a larger effect on interlaminar shear strength (ILSS) than on compression strength and flexible strength of Needling C-C(NC-C). The mechanical properties of NC-C increased with increasing punching density in the range of 20-45 punch/cm2 and also with increasing punching depth range from10 to16mm. The NC-C with the highest ND value of 55punch/cm2 had highest ILSS value of 27 MPa.The optimized ND and PD parameters was 30 punch/cm2 and 12mm respectively, which resulted in a high value of tensile strength(119MPa), bending strength (220MPa) and compression strength (235 MPa) in the X-Y direction .

scholarly journals Near infrared spectroscopy for assessing mechanical properties of Castanea sativa wood samples

2019 ◽  
Vol 50 (4) ◽  
pp. 191-197 ◽  
Author(s):  
Manuela Mancini ◽  
Elena Leoni ◽  
Michela Nocetti ◽  
Carlo Urbinati ◽  
Daniele Duca ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Infrared Spectroscopy ◽  
Near Infrared Spectroscopy ◽  
Near Infrared ◽  
Bending Strength ◽  
Prediction Models ◽  
Castanea Sativa ◽  
Modulus Of Rupture ◽  
Current Standard ◽  
Standard Samples

Near infrared spectroscopy (NIR) is a technique widely used for the prediction of different chemical-physical features of wood. In this study, the technique was used to assess its potential to predict the mechanical characteristics of wood. Castanea sativa samples of three different European provenances were collected and laboratory tests were performed to assess the mechanical properties of wood samples. Modulus of elasticity (MOE), load-deflection curve and modulus of rupture (MOR) were calculated by using INSTRON machine with three points bending strength with elastic modulus, while density (D) was calculated according to the current standard. Samples were then analysed by means of NIR spectroscopy. The raw spectra were pre-processed and regression models were developed. Variables selection techniques were used to improve the model performance. In detail, MOE regression model returned an error of 696.01 MPa (R2=0.78). Instead, MOR and D prediction models must be further investigated on a wider number of samples considering the high variability in physical characteristics of chestnut wood. The results demonstrated the possibility to use NIR technique for the prediction of the mechanical properties of wood providing useful indications in evaluation-screening processes. Indeed, the presence of the principal wood compounds (cellulose, hemicellulose and lignin) and their influence in the characterisation of mechanical stress reactions were confirmed.

Engineered Wood Composite of Laminated Veneer Lumber: Physical and Mechanical Properties

2016 ◽  
Vol 842 ◽  
pp. 103-128
Author(s):  
Kang Chiang Liew ◽  
Singan Grace
Keyword(s):  
Mechanical Properties ◽  
Shear Strength ◽  
Moisture Content ◽  
Bending Strength ◽  
Physical And Mechanical Properties ◽  
P Value ◽  
Thickness Swelling ◽  
Laminated Veneer Lumber ◽  
Physical Testing ◽  
Acacia Hybrid

Utilisation of forest plantation species such as Acacia hybrid has been used in wood-based industry as an alternative to solid wood that was usually attained from natural forest. While, the under-utilised species such as Mangifera sp. is not often been used as raw material for wood products, in this study, laminated veneer lumber (LVL) has been produced from Acacia hybrid and Mangifera sp. The physical and mechanical properties of LVL were determined and compared. For physical testing, the range value of moisture content was 9.41% to 14.56%, Density was 487.90 kg/m3 to 699.10 kg/m3, thickness swelling was between 0.20% to 6.05%, water absorption between 32.71% to 91.25%, and rate of delamination from 0% to 100%. Mangifera sp. LVL has higher moisture content, rate of delamination, and water absorbency. In mechanical testing, it is been found that Acacia hybrid LVL has overall higher strength compared to Mangifera sp. LVL, in terms of static bending strength (MOR and MOE), shear strength, and compression strength. Range of value for MOR was between 10.27 N/mm2 to 129.99 N/mm2, MOE between 1138 N/mm2 to 16472.93 N/mm2, shear strength between 0.43 N/mm2 to 3.40 N/mm2, and compression between 139.45 N/mm2 to 6749.74 N/mm2. For physical testing, the overall result of p-value for moisture content, water absorption, and delamination were significant at p ≤ 0.05, while density and thickness swelling were not significant at p ≥ 0.05. For overall result, the p-value for static bending strength (MOR and MOE) was significant at p ≤ 0.05 while for shear strength and compression strength were not significant at p ≥ 0.05.

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 Decay Process Characteristics and Fungal Community Composition of Salix psammophila Sand Barriers in an Arid Area, Northern China

2021 ◽  
Vol 13 (14) ◽  
pp. 7590
Author(s):  
Xia Yang ◽  
Yumei Liang ◽  
Yong Gao ◽  
Ruidong Wang
Keyword(s):  
Mechanical Properties ◽  
Fungal Community ◽  
Basic Density ◽  
Physical And Mechanical Properties ◽  
Decay Process ◽  
Fungal Communities ◽  
Modulus Of Rupture ◽  
Chemical Components ◽  
Physical Parameters ◽  
Mechanical Index

With the increase in setting years in deserts, Salix psammophila sand barriers with different degrees of lodging damage caused by decay are losing wind-prevention and sand-fixation properties. In this study, we focus on the change in chemical properties of soils, and physical and mechanical properties of plants along different setting years; meanwhile, the change in fungal communities has been analyzed using high-throughput sequencing technology. The results show that a change in physical and mechanical properties and the loss of primary chemical components led to the degradation of the protective properties of the barrier to different degrees. After five years of setting, the physical parameters of basic density and shrinkage rate decreased by 44.04% and 28.68%, respectively, and the loss of the modulus of rupture mechanical index declined by 62.72%. After seven years of setting, the mechanical indexes of the modulus of rupture decreased by 76.95%. Five and seven years represented important inflection points in the decay process. Sordariomycetes (53.75%) and Eurotiomycetes (19.78%) were the main fungal groups present during the decay of the sand barrier. The basic density, moisture content, cellulose, and lignin of the sand barrier were the main driving factors affecting the distribution of fungal communities. The mechanism on fungal community to the decay of sand barriers still needs further studies to keep the function of sand barriers in fragile desert ecosystems.

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