scholarly journals MOR and MOE of Serbian Spruce (Picea omorika Pančić/Purkyně) Wood from Natural Stands

2021 ◽  
Vol 72 (2) ◽  
pp. 193-200
Author(s):  
Danijela Petrović ◽  
Vojislav Dukić Dukić ◽  
Zdravko Popović ◽  
Nebojša Todorović
Keyword(s):  
Modulus Of Elasticity ◽  
Ring Width ◽  
Modulus Of Rupture ◽  
Bending Stress ◽  
Annual Ring Width ◽  
Spruce Wood ◽  
Picea Omorika ◽  
Natural Stands ◽  
Serbian Spruce ◽  
Proportionality Limit

The paper presents the results of testing the bending stress of Serbian spruce wood from natural stands. In testing the samples, in addition to the modulus of rupture, the bending stress at the proportionality limit, the ratio between the stress at the proportionality limit and the modulus of rupture as well as the modulus of elasticity of wood were determined. The study included nine trees from natural stands, and a total of 261 samples were tested. Regression analysis determined the dependences of these mechanical properties on the annual ring width, the proportion of late wood and wood density, as well as the dependence of the modulus of elasticity on the modulus of rupture.

scholarly journals Compression strength perpendicular to grain of Serbian spruce (Picea omorika (Pancic) purkyně) wood from plantations and natural stands

2017 ◽  
pp. 171-188
Author(s):  
Danijela Petrovic ◽  
Zdravko Popovic ◽  
Nebojsa Todorovic
Keyword(s):  
Mechanical Properties ◽  
Regression Analysis ◽  
Tangential Direction ◽  
Annual Rings ◽  
Spruce Wood ◽  
Limit Strength ◽  
Picea Omorika ◽  
Natural Stands ◽  
Serbian Spruce ◽  
Conditional Limit

This paper presents the results of testing the compression of Serbian spruce wood from plantations and natural stands. Compression perpendicular to grain in radial and tangential direction was tested. A dilatation of 1% was taken for a conditional boundary dilatation, and the appropriate strength for the conditional limit strength was taken. Six trees from plantations and nine trees from natural stands were analyzed. In total, 309 samples were tested. The regression analysis examined the dependence of these mechanical properties on the width of the annual rings, the percentage of late wood and wood density.

Modelling the variation in modulus of elasticity and modulus of rupture of Scots pine round timber

2010 ◽  
Vol 40 (4) ◽  
pp. 668-678 ◽  
Author(s):  
Olav Høibø ◽  
Geir I. Vestøl
Keyword(s):  
Modulus Of Elasticity ◽  
Ring Width ◽  
Modulus Of Rupture ◽  
Residual Variance ◽  
Annual Ring Width ◽  
Single Tree ◽  
Breast Height ◽  
Load Carrying ◽  
Southern Norway ◽  
Tree Characteristics

Recovery from the forest-wood chain is directly influenced by how different qualities of logs are used. Logs used directly as load-carrying members in structures are products in which MOE (modulus of elasticity when bending) and MOR (modulus of rupture) are of great importance. To achieve a more optimal bucking process in the forest, models that enable such presorting of logs for quality are desirable. In all, 533 logs from 150 trees were sampled from 10 stands with different site indices and altitudes in southern Norway. Models were developed that predicted MOE and MOR by using different stand and tree characteristics. The MOR models were compared with a model including MOE alone and a model including both MOE and different tree characteristics. The study showed that it may be a good option to combine different tree and stand characteristics with MOE. MOE and the single-tree variables diameter at breast height and mean annual ring width at breast height most reduced the residual variance when MOR was modelled. The study also showed that it is possible to perform a coarse sorting by simple stand and single-tree characteristics.

scholarly journals Anisotropy of transversal swelling of Serbian spruce wood (Picea omorika (Pancic) Purkyně)

2018 ◽  
pp. 119-136
Author(s):  
Danijela Petrovic ◽  
Zdravko Popovic ◽  
Nebojsa Todorovic ◽  
Vojislav Dukic
Keyword(s):  
Regression Analysis ◽  
Growth Rings ◽  
Spruce Wood ◽  
Late Wood ◽  
Picea Omorika ◽  
Natural Stands ◽  
Serbian Spruce

The paper presents the results of analysis of anisotropy of transverse swelling of the Serbian spruce wood. The analysis included six trees that come from plantations and nine trees from natural stands of Serbian spruce, and a total of 3098 samples were tested. The results show a change in transversal anisotropy at the height of the tree, as well as its change in radius. The dependence of this property on the growth rings width, the participation of late wood and the density of wood was determined by regression analysis.

scholarly journals MECHANICAL PROPERTIES OF POLISH-GROWN PINUS SYLVESTRIS L. STRUCTURAL SAWN TIMBER FROM THE BUTT, MIDDLE AND TOP LOGS

Wood Research ◽  
2021 ◽  
Vol 66 (2) ◽  
pp. 231-242
Author(s):  
Sławomir Krzosek ◽  
Marek Grześkiewicz ◽  
Izabela Burawska Kupniewska ◽  
Piotr Mańkowski ◽  
Marek Wieruszewski
Keyword(s):  
Mechanical Properties ◽  
Pinus Sylvestris ◽  
Modulus Of Elasticity ◽  
Ring Width ◽  
Modulus Of Rupture ◽  
Bending Test ◽  
Average Growth ◽  
Growth Ring Width ◽  
Annual Growth Rings ◽  
Sawn Timber

The research consisted in testing Polish sawn timber dedicated for construction applications made of pines (Pinus sylvestris L.) that grew in the Silesian Forestry Region, taking into account three parts of the log: butt, middle and top. The boards had the same cross section, a nominal thickness of 40 mm and width of 138 mm, typical for Polish structural timber. The mean nominal length of the boards under research amounted to 3500 mm. Each set was composed of 70 boards. Before the tests, boards were dried in an industrial drier until reaching the moisture content of 12%, and they were planed on 4 sides. First of all, the sawn timber was graded into strength classes, and their dynamic modulus of elasticity (MOE_dyn) was tested with a non-destructive method, with the use of a portable MTG device. The next step consisted in a bending test with four points of support, according to the EN 408 standard, and with the use of the TiraTest 2300 machine, in order to determine the global modulus of elasticity (MOE_EN-408) and the static bending strength, also referred to as modulus of rupture (MOR). Finally, the average growth ring width was determined for each board (PN-D-94021), as well as wood density according to EN-408. The hereby paper presents the test results for all the tested sawn timber boards, taking into account the part of log that each board came from: butt, middle or top. The hereby paper presents the influence of density on the mechanical properties of wood, taking into account the location on the round timber. The analysis does not include the influence of the width of annual growth rings and the proportion of latewood on the wood properties under research.

Pengaruh Tekanan dan Penggunaan Conplast terhadap Sifat Mekanik Eternit dari Abu Cangkang Sawit

2016 ◽  
Vol 8 (15) ◽  
pp. 47-54
Author(s):  
Haspiadi Haspiadi
Keyword(s):  
Mechanical Properties ◽  
Oil Palm ◽  
Modulus Of Elasticity ◽  
Modulus Of Rupture ◽  
Palm Shell ◽  
Oil Palm Shell ◽  
Density Values ◽  
Test Result

The purpose of this research is to know the influence of pressure and use of conplast against mechanical properties which are a Modulus of Elasticity (MOE) and Modulus of Rupture (MOR) of plasterboard. The study is done because still low quality of plasterboard made from a mixture of ashes of oil-palm shell especially of the mechanical properties compared to the controls. The method of this reserach used variation of printed pressure and the addition of conplast. Test result is obtained that the highest value of Modulus of Elasticity (MOE) 90875.94 Kg/cm2, Modulus of Rupture (MOR) 61.16 Kg/cm2 and density values in generally good printed at the pressure 60 g/cm3 and the addition of conplast 25% as well as the composition of the ash of palm shell oil 40%: limestone 40%: cement 15%: fiber 5% and 300 mL of water. ABSTRAK Tujuan dari penelitian ini adalah untuk mengetahui pengaruh tekanan dan penggunaan conplast terhadap sifat mekanik yaitu kuat lentur dan keteguhan patah eternit berbahan dasar abu cangkang sawit. Penelitian ini dilakukan karena masi rendahnya mutu eternit berbahan campuran abu cangkang sawit dari bolier khususnya sifat mekanik dibandingkan dengan kontrol. Metode penelitian yang digunakan adalah dengan variasi tekanan cetak dan penambahan conplast. Hasil uji diperoleh bahwa kuat lentur tertinggi sebesar 90875,94 Kg/cm2 dan keteguhan patah sebesar 61,16 Kg/cm2, yang dicetak pada tekanan 60 g/cm3 dan penambahan conplast 25% dengan komposisi  abu cangkang sawit 40 %: kapur 40 % : semen 15 %: serat 5 % dan air 300 mL.Kata Kunci :  Abu cangkang sawit, conplast, kuat lentur, keteguhan patah.

DISTRIBUTIONS OF MODULUS OF ELASTICITY AND MODULUS OF RUPTURE IN FOUR MILL RUN LUMBER POPULATIONS

2019 ◽  
Vol 51 (2) ◽  
pp. 183-192 ◽  
Author(s):  
Frank C Owens ◽  
Steve P Verrill ◽  
Rubin Shmulsky ◽  
Robert J Ross
Keyword(s):  
Modulus Of Elasticity ◽  
Modulus Of Rupture

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.

Mechanical Properties and Decay Resistance of Wood Polymer Composites (WPC)

2011 ◽  
Vol 264-265 ◽  
pp. 819-824 ◽  
Author(s):  
Md. Rezaur Rahman ◽  
Sinin Hamdan ◽  
M. Saiful Islam ◽  
Md. Shahjahan Mondol
Keyword(s):  
Polymer Composites ◽  
Young’S Modulus ◽  
Modulus Of Elasticity ◽  
Young's Modulus ◽  
Decay Resistance ◽  
Modulus Of Rupture ◽  
Wood Polymer ◽  
Static Young’S Modulus ◽  
Wood Polymer Composites ◽  
Wood Polymer Composite

In Malaysia, especially Borneo Island Sarawak has a large scale of tropical wood species. In this study, selected raw tropical wood species namely Artocarpus Elasticus, Artocarpus Rigidus, Xylopia Spp, Koompassia Malaccensis and Eugenia Spp were chemically treated with sodium meta periodate to convert them into wood polymer composites. Manufactured wood polymer composites were characterized using mechanical testing (modulus of elasticity (MOE), modulus of rupture (MOR), static Young’s modulus) and decay resistance test. Modulus of elasticity and modulus of rupture were calculated using three point bending test. Static Young’s modulus and decay resistance were calculated using compression parallel to gain test and natural laboratory decay test respectively. The manufactured wood polymer composites yielded higher modulus of elasticity, modulus of rupture and static Young’s modulus. Wood polymer composite had high resistant to decay exposure, while Eugenia Spp wood polymer composite had highly resistant compared to the other ones.

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.

scholarly journals Effects of ring characteristics on the compressive strength and dynamic modulus of elasticity of seven softwood species

Holzforschung ◽  
2007 ◽  
Vol 61 (4) ◽  
pp. 414-418 ◽  
Author(s):  
Cheng-Jung Lin ◽  
Ming-Jer Tsai ◽  
Chia-Ju Lee ◽  
Song-Yung Wang ◽  
Lang-Dong Lin
Keyword(s):  
Compressive Strength ◽  
Statistical Analysis ◽  
Modulus Of Elasticity ◽  
Dynamic Modulus ◽  
Ring Width ◽  
Ring Density ◽  
Dynamic Modulus Of Elasticity ◽  
Wave Technique ◽  
Wood Strength ◽  
Softwood Species

Abstract The effects of ring characteristics on the compressive strength and dynamic modulus of elasticity of seven softwood species in Taiwan were examined. The results revealed good correlation between compressive strength and dynamic modulus of elasticity obtained using an ultrasonic wave technique (correlation coefficient r=0.77–0.86). Overall, compressive strength increased with decreasing ring width parameters and increasing ring density parameters. Ring density was related to compressive strength, but was not the sole factor affecting the wood strength. According to our statistical analysis, compressive strength was affected by various ring characteristics. Relationships between ring characteristics and compressive strength are influenced by the anatomic direction. Results revealed that earlywood density and minimum density in a ring are equally important variables for evaluating the compressive strength of wood.

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