scholarly journals Comparative Assessment Of Some Physical And Mechanical Properties Of Wood Of Different Scots Pine Climatypes

2021 ◽  
Vol 24 (2) ◽  
pp. 27-36
Author(s):  
Siarhei Rabko ◽  
Aliaksandr Kozel ◽  
Ivan Kimeichuk ◽  
Vasyl Yukhnovskyi
Keyword(s):  
Mechanical Properties ◽  
Scots Pine ◽  
Bending Strength ◽  
Geographical Origin ◽  
Testing Machine ◽  
Physical And Mechanical Properties ◽  
Forest Steppe ◽  
Siberian Pine ◽  
North Latitude

For a more efficient and rational use in the production of Scots pine wood of various geographical origin, it is necessary to know its physical and mechanical properties. The purpose of this study was to determine the physical and mechanical properties of wood of 17 climatic ecotypes of Scots pine and to carry out a comparative analysis of the indicators obtained for the studied climatypes separately and when they are grouped into subspecies in accordance with the classification of L.F. Pravdin. The range of the geographical origin of the places of seed procurement is from 47 to 62° north latitude and from 22 to 85° east longitude. The modern density universal testing machine MTS INSIGHT 100 was used for research. As a result of the research, it was found that the density of wood in an absolutely dry state varies from 370 kg/m3 (Kursk climatype) to 524 kg/m3 (Volgograd climatype), and at 12% humidity – from 397 kg/m3 (Kursk climatype) to 550 kg/m3 (Volgograd climatype). The index of the strength of wood of the studied climatypes for compression along the fibres was from 32 MPa (Kursk climatype) to 54 MPa (Volgograd climatype), and for static bending – from 55 to 92 MPa for the Vologda and Ulyanovsk climatypes, respectively. Distribution of Scots pine climatypes into subspecies in accordance with the classification of L.F. Pravdin and the obtained data on the physical and mechanical properties of wood have a certain pattern. The maximum density of wood at 12% moisture is typical for the European Scots pine subspecies is 497±8 kg/m3 , the minimum value of this indicator for the Siberian Scots pine subspecies is 423±30 kg/m3 . An intermediate position is occupied by the subspecies of Lapland pine and Forest-steppe pine with values of 483±16 and 464±12 kg/m3 , respectively. The strength index of wood in the studied subspecies for compression along the fibres ranged from 47±1 MPa (European subspecies) to 33±4 MPa (Siberian subspecies), in the Lapland pine subspecies – 44±2 MPa and somewhat lower in the Forest-steppe pine subspecies – 42±2 MPa. The maximum value of the static bending strength of wood is typical for the European pine subspecies – 78±4 MPa, and the minimum – for the Siberian pine subspecies – 61±14 MPa. This indicator turned out to be equal in subspecies of forest-steppe and Lapland pine and amounted to 72±4 MPa. The practical value of the work lies in identifying the existing differences and variability among climatypes according to the studied physical and mechanical properties of wood and selecting the most promising of them for further breeding purposes

scholarly journals Selected physical and mechanical properties of Scots pine (Pinus sylvestris L.) wood from stands of younger age classes as criteria for rational utilization of timber

2021 ◽  
Vol 27 (1) ◽  
Author(s):  
Przemysław Marcin Pikiński ◽  
Jaroslav Szaban ◽  
Gerda Šilingienė ◽  
Robert Korzeniewicz ◽  
Witold Pazdrowski
Keyword(s):  
Mechanical Properties ◽  
Pinus Sylvestris ◽  
Scots Pine ◽  
Bending Strength ◽  
Physical And Mechanical Properties ◽  
Growth Conditions ◽  
Tree Age ◽  
Coniferous Forests ◽  
Forest Site ◽  
Quality Coefficient

The aim of this study was to assess the quality of Scots pine (Pinus sylvestris L.) wood depending on the age of trees, forest site conditions and social class of tree position in the stand. Analyses were based on the determination of specific density and static bending strength, as well as the strength quality coefficient. It was to determine changes in physical and mechanical properties of timber depending on tree age as well as growth conditions reflected in the forest site such as fresh mixed coniferous forests and fresh mixed broadleaved forests. Experimental plots were established in 6 localities with 30, 40 and 60-year-old trees. In each of the stands, a 1-hectare experimental plot was established. Based on the measured DBH and tree height, dimensions of three mean sample trees were calculated, while the classification of social class of tree position in the stand developed by Kraft (1884) was also applied. Analyses were conducted on wood samples with 12% moisture content. Strength tests on wood samples were performed on an Instron 33RH204 universal strength testing machine. A detailed analysis showed properties of pine wood are improved with an increase of tree age in both forest sites. Statistically significant differences were observed for wood density and static bending strength. More advantageous properties were observed for wood of pines from the less fertile forest site, i.e., fresh mixed coniferous forests. Density and static bending strength were markedly determined by tree age and growth conditions. The static bending strength quality coefficient from pines growing in the fresh mixed coniferous forests increased between 30 and 40 years, similarly as it was for the fresh mixed broadleaved forests, while between 40 and 60 years, it deteriorated for the fresh mixed coniferous forests. Wood density from the fresh mixed coniferous forests was by 3% to 7% greater than pines growing in fresh mixed broadleaved forests. In turn, static bending strength of wood from pines growing in fresh mixed coniferous forests was by 4% to 10% greater than trees from the fresh mixed broadleaved forests.  Keywords: Scots pine, wood properties, forest site, Poland

scholarly journals Quality and Bending Properties of Scots Pine (Pinus Sylvestris L.) Sawn Timber

Forests ◽  
2020 ◽  
Vol 11 (11) ◽  
pp. 1200
Author(s):  
Izabela Burawska-Kupniewska ◽  
Sławomir Krzosek ◽  
Piotr Mańkowski ◽  
Marek Grześkiewicz
Keyword(s):  
Mechanical Properties ◽  
Scots Pine ◽  
Modulus Of Elasticity ◽  
Bending Strength ◽  
Mechanical Parameters ◽  
Bending Properties ◽  
Characteristic Values ◽  
Sawn Timber ◽  
The Moment

The paper presents the partial research results of a mechanical properties study conducted on Scots pine from the Silesian Forestry Area in Poland. The scope of research included the visual strength grading of the timber according to the PN-D-94021:2013 standard, mechanical testing (according to EN 408:2012) and an attempt to assign visuals to the C strength classes. The EN 1912: 2012 standard assigns the visual sorting classes of individual wood species (according to national sorting standards) to the C strength classes introduced by the EN 338: 2018 standard. At the moment, this standard does not assign Polish visual sorting classes (KW, KS, and KG) to C strength classes. The obtained MOE (modulus of elasticity) and MOR (static bending strength) values were corrected according to the EN 384:2018 standard, and their characteristic values were later calculated. On this basis, we proposed a classification of the grading classes determined on the basis of PN-D-94021 into C classes described in EN 338:2018, which is necessary in the process of the transposition of Polish strength grades (KW, KS, KG, and Reject) and the qualification of them in line with EN 1912:2012. The calculated characteristic values of density, MOR and E0 (the modulus of elasticity parallel to the grain) allowed us to assign Polish visual grades KW, KS, and KG to C35, C30, and C20, respectively. The pine timber under research had high physical and mechanical parameters, which translated into high C classes to which the KW, KS, and KG timber categories were assigned.

scholarly journals The Influence of Scots Pine Log Type (Pinus sylvestris L.) on the Mechanical Properties of Lumber

Forests ◽  
2020 ◽  
Vol 11 (12) ◽  
pp. 1257
Author(s):  
Sławomir Krzosek ◽  
Izabela Burawska-Kupniewska ◽  
Piotr Mańkowski
Keyword(s):  
Mechanical Properties ◽  
Scots Pine ◽  
Bending Strength ◽  
Geographical Origin ◽  
Mixed Forest ◽  
Geographic Origin ◽  
Limited Extent ◽  
Static Modulus ◽  
Different Types ◽  
Static Modulus Of Elasticity

The paper presents an analysis of the influence of geographical origin and Scots pine log type on the mechanical properties of the timber sawn from them. The tested timber was sawn from logs obtained from three different forestry regions in Poland, located in the western part of the country. A batch of 150 timber pieces was obtained from each region. The cross-section had the dimensions of 40 mm × 138 mm. The timber was sawn from logs of three different types: butt, middle and top, from a fresh, mixed forest around 120 years old. The timber was dried in industrial conditions and planed four times. The values determined for the timber under research were the static modulus of elasticity in bending (MOE), and the bending strength (MOR). Moreover, timber density (DEN) was determined with the stereometric method. For all three sites, the highest average values of the tested timber properties were obtained for timber made of butt logs, and the lowest for timber made of top logs. It was concluded that the tested Scots pine properties depended on the type of log, and to limited extent, on its geographic origin. The statistical analysis revealed that the geographic origin of the logs that the tested timber was made of had a statistically significant impact on the variance of all the tested timber properties. The type of log also had a statistically significant influence on the variance of all the tested properties.

scholarly journals Influence of Scots Pine (Pinus sylvestris L.) Veneers Quality on Selected Properties of Layered Composite for Flooring Materials

Forests ◽  
2021 ◽  
Vol 12 (8) ◽  
pp. 1017
Author(s):  
Izabela Burawska-Kupniewska ◽  
Paweł Mycka ◽  
Piotr Beer
Keyword(s):  
Mechanical Properties ◽  
Pinus Sylvestris ◽  
Scots Pine ◽  
Modulus Of Elasticity ◽  
Bending Strength ◽  
Deformation Modulus ◽  
Physical And Mechanical Properties ◽  
Production Costs ◽  
Base Layer ◽  
Class A

The article concerns the quality issues in wood industry, and especially the advisability of removing defects from veneers. The research purpose of the study was to analyse the influence of the layered structure of plywood base layer made of low-quality wood on selected mechanical properties of floor composites. The utilitarian purpose is to analyse the possibility of producing floors from low-quality materials reducing waste. Four quality classes of Scots pine veneers (Pinus sylvestris L.) were taken into account: A, B, C, D, from the highest class-A without defects to the lowest class-D characterized by a lot of knots (including broken and falling out ones) and cracks. The base layer of the floors was made of these wood quality classes. The value of the modulus of elasticity in elastic deformation, modulus of elasticity in the dynamic and fatigue tests, stiffness and static bending strength were investigated. The test results showed that, as expected, the samples made of class A had the highest values of the measured parameters (static bending strength, static and dynamic modulus of elasticity, and stiffness). However, the values of the tested parameters for the remaining classes B, C, and D did not significantly differ. It was concluded from the research that the change of the plywood base layer conditions regarding the quality of veneers does not significantly affect the physical and mechanical properties of composites. Hence, it is possible to use wood of lower quality classes for production without verification of which class they belong to, which will significantly reduce the production costs.

Structure and properties of compact articles from high-alloyed iron powder with adding of boron nitride

2020 ◽  
pp. 39-48
Author(s):  
B. O. Bolshakov ◽  
◽  
R. F. Galiakbarov ◽  
A. M. Smyslov ◽  
◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Boron Nitride ◽  
Grain Boundary ◽  
Bending Strength ◽  
Physical And Mechanical Properties ◽  
Operating Conditions ◽  
Structure And Properties ◽  
Steam Turbines ◽  
Friction Forces ◽  
Wide Range

The results of the research of structure and properties of a composite compact from 13 Cr – 2 Мо and BN powders depending on the concentration of boron nitride are provided. It is shown that adding boron nitride in an amount of more than 2% by weight of the charge mixture leads to the formation of extended grain boundary porosity and finely dispersed BN layers in the structure, which provides a high level of wearing properties of the material. The effect of boron nitride concentration on physical and mechanical properties is determined. It was found that the introduction of a small amount of BN (up to 2 % by weight) into the compacts leads to an increase in plasticity, bending strength, and toughness by reducing the friction forces between the metal powder particles during pressing and a more complete grain boundary diffusion process during sintering. The formation of a regulated structure-phase composition of powder compacts of 13 Cr – 2 Mо – BN when the content of boron nitride changes in them allows us to provide the specified physical and mechanical properties in a wide range. The obtained results of studies of the physical and mechanical characteristics of the developed material allow us to reasonably choose the necessary composition of the powder compact for sealing structures of the flow part of steam turbines, depending on their operating conditions.

scholarly journals Eco-Friendly, High-Density Fiberboards Bonded with Urea-Formaldehyde and Ammonium Lignosulfonate

Polymers ◽  
2021 ◽  
Vol 13 (2) ◽  
pp. 220
Author(s):  
Petar Antov ◽  
Viktor Savov ◽  
Ľuboš Krišťák ◽  
Roman Réh ◽  
George I. Mantanis
Keyword(s):  
Mechanical Properties ◽  
Bending Strength ◽  
Urea Formaldehyde ◽  
Physical And Mechanical Properties ◽  
High Density ◽  
Thickness Swelling ◽  
Formaldehyde Content ◽  
Uf Resin ◽  
Natural Wood ◽  
European Standards

The potential of producing eco-friendly, formaldehyde-free, high-density fiberboard (HDF) panels from hardwood fibers bonded with urea-formaldehyde (UF) resin and a novel ammonium lignosulfonate (ALS) is investigated in this paper. HDF panels were fabricated in the laboratory by applying a very low UF gluing factor (3%) and ALS content varying from 6% to 10% (based on the dry fibers). The physical and mechanical properties of the fiberboards, such as water absorption (WA), thickness swelling (TS), modulus of elasticity (MOE), bending strength (MOR), internal bond strength (IB), as well as formaldehyde content, were determined in accordance with the corresponding European standards. Overall, the HDF panels exhibited very satisfactory physical and mechanical properties, fully complying with the standard requirements of HDF for use in load-bearing applications in humid conditions. Markedly, the formaldehyde content of the laboratory fabricated panels was extremely low, ranging between 0.7–1.0 mg/100 g, which is, in fact, equivalent to the formaldehyde release of natural wood.

Studies on Nanostructured Polyurethane/Clay Interpenetrating Polymer Networks

2005 ◽  
Vol 475-479 ◽  
pp. 1001-1004
Author(s):  
Ninglin Zhou ◽  
Xiao Xian Xia ◽  
Li Li ◽  
Shao Hua Wei ◽  
Jian Shen
Keyword(s):  
Mechanical Properties ◽  
Polymer Networks ◽  
Testing Machine ◽  
Physical And Mechanical Properties ◽  
Interpenetrating Polymer Networks ◽  
Absorption Properties ◽  
Tensile Testing Machine ◽  
Swelling Agent ◽  
Silicate Layers ◽  
Polyurethane Matrix

A novel exfoliated polyurethane (PU)/clay Interpenetrating Polymer Networks (IPNs) nanocomposite has been synthesized with polyurethane and organoclay. MTPAC is used as swelling agent to treat Na-montmorillonite for forming organoclay. The results indicate that there is very good compatibility between organoclay and PU. Nanoscale silicate dispersion was analyzed by XRD. The mechanical properties of the nanocomposites have been measured by tensile testing machine. The nanocomposites show obviously improved physical and mechanical properties when compared with the pure polymer. Additionally, PU /MTPAC- clay shows lower water absorption properties than pure PU do. In addition, the reinforcing and intercalating mechanism of silicate layers in polyurethane matrix are discussed.

scholarly journals Regression analysis and statistical examination of Knoop Hardness on abrasion resistance in Lyca Beige Marbles

Filomat ◽  
2020 ◽  
Vol 34 (2) ◽  
pp. 609-614
Author(s):  
Burcu Aydin ◽  
Fusun Yalcin ◽  
Ozge Ozer ◽  
Gurhan Yalcin
Keyword(s):  
Mechanical Properties ◽  
Regression Analysis ◽  
Physical And Mechanical Properties ◽  
Production Method ◽  
Knoop Hardness ◽  
Decomposition Products ◽  
Marble Quarries ◽  
Selection Of

Marbles are secondary decomposition products formed by metamorphism of limestone. Effective classification of marble quarries in terms of quality enables the selection of a sustainable production method and safety application. This evaluation is based on physico-mechanical properties of the samples. Obtained results of physico-mechanical properties of the marbles were statistically analyzed using Stata 14 and SPSS 21 software. The marbles indicated mostly normal physical and mechanical properties. A strong inverse relationship exists between Abrasion Value and Knoop Hardness Determination that indicates a significant nonlinear relationship. Samples were distinguished into 3 groups of close similarity and related properties. The estimated value of the parameters is in the 95 % confidence interval. The equation obtained by regression analysis was used for the determination of resistance to abrasion.

scholarly journals METHOD OF SAMPLE MANUFACTURING FROM MULTILAYER COMPOSITE MATERIALS FOR STUDYING THEIR MECHANICAL PROPERTIES

2018 ◽  
pp. 16-23
Author(s):  
Alsaid Mazen ◽  
Ali Salamekh
Keyword(s):  
Mechanical Properties ◽  
Composite Materials ◽  
Polymer Composite ◽  
Testing Machine ◽  
Physical And Mechanical Properties ◽  
Polymer Composite Materials ◽  
Technological Parameters ◽  
Cutting Out ◽  
Method Of Production ◽  
Economic Considerations

In the last decades there is increasing the need to apply polymer composite materials in different industries, particularly in shipbuilding. There are developing single structures made from polymer composite materials to be used on board ships. The article focuses on technology of manufacturing slabs from polymer composite materials to carry out mechanical testing in the laboratory special standard units. Mechanical properties of polymer composite materials depend on molding technologies. There has been described a technology of sample manufacturing from polymer composite materials reinforced with glass fiber mat with fiberglass plastics. The technique of testing the specified samples for tensile strength has been considered. The sizes and shapes of the samples as well as the technological parameters of the manufacturing process have been validated, depending on the standard requirements and the technological features of the testing machine. The physical and mechanical properties of the components that make up the composite materials are considered. The sequence of stacking layers for preparation of plates from composite materials is indicated. The dimensions of the plates for cutting out finished samples are determined, depending on the method of production. The way of laying plates from composite materials has been chosen on the base of economic considerations and conditions of accessibility. The obtained results of mechanical properties can be used in solving problems of application of polymer composite materials in shipbuilding, for example, in manufacturing superstructures of some dry cargo vessels.

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