Mechanical Characterization of Iroko Wood Using Small Specimens

Despite their favorable physical and mechanical properties for structural use, tropical woods, such as Iroko (Milicia excelsa), present knowledge gaps to be filled mainly about their mechanical characterization, which currently limit their use or result in under- or overdimensioned structural elements. Visual classification, one of the most used methods for characterizing wood, is inaccurate in the case of Iroko due to the wide variety of geographical locations in which this species can be found. In addition, mechanical characterization using test pieces with structural dimensions leads to high and impractical costs. In this context, this study aims to verify the mechanical properties of Iroko (imported from the Republic of the Congo) from small size specimens, a process that is currently standardized only for softwoods, and to verify the correlation of different properties through bending properties and ultrasound tests. Prior to the bending tests, the speed of propagation of ultrasonic waves was measured using the direct method. The results obtained show a good correlation between density and bending properties and the velocity of propagation of ultrasonic waves.

Download Full-text

Influence of 6PPD Stabilizer on Climatic Stability of Rubbers Based on Butadiene-Nitrile and Epichlorohydrin Rubbers

Materials Science Forum ◽

10.4028/www.scientific.net/msf.945.433 ◽

2019 ◽

Vol 945 ◽

pp. 433-437

Author(s):

M.D. Sokolova ◽

A.F. Fedorova ◽

M.L. Davydova

Keyword(s):

Mechanical Properties ◽

Physical And Mechanical Properties ◽

Hydraulic Fluids ◽

Open Ground ◽

The Republic ◽

The Stability ◽

Property Changes ◽

Full Scale Tests ◽

Butadiene Nitrile Rubber ◽

Hydrocarbon Media

The present paper outlines the results of full-scale tests of climatic stability and the study of resistance to the action of hydrocarbon media of rubbers based on BNKS-18-18 (butadiene-nitrile rubber) and Hydrin T6000 epichlorohydrin rubber containing one of 6PPDstabilizerwith an aromatic amine moiety widely used in synthetic rubbers. Samples are exposed in an open ground under natural conditions of exposure to climatic external factors of Yakutsk in the Republic of Sakha (Yakutia), as well as in the oil environment of Talakanskoye field and I-50A hydraulic fluid in an unheated room. Such indexes of the samples as conditional tensile strength, elongation at rupture, hardness and degree of swelling are measured to determine the resistance of rubbers to aging after the first, third, and sixth months of exposing. The results of the study reveal the contribution of 6PPD stabilizer in maintaining the stability of the physical and mechanical properties of BNKS-18: rubber containing 6PPD has less property changes both in the open air and in hydrocarbon media compared to rubber without a stabilizer. It should be noted that the oil environment is the most aggressive environment, the swelling of rubbers in oil leads to a significant reduction in strength due to a decrease in intermolecular interaction.6PPD stabilizer occurred less effective for the rubber based on Hydrin T6000: changes in properties of the samples containing the stabilizer are larger than those of the samples without the stabilizer. However, unlike BNKS-18-18-based rubber, the swelling of rubber based on Hydrin T6000 led to the greatest stability of the physical and mechanical properties in the oil environment compared to the open air and hydraulic fluids.

Download Full-text

Mechanical Characterization of Angustifolia Kunth and Rayada Amarilla Guadua Bamboo

MATEC Web of Conferences ◽

10.1051/matecconf/201930303002 ◽

2019 ◽

Vol 303 ◽

pp. 03002

Author(s):

Brayan García ◽

Camila Preciado ◽

Mónica Bedoya ◽

Oscar Mendoza

Keyword(s):

Mechanical Properties ◽

Mechanical Characterization ◽

Construction Material ◽

Construction Materials ◽

Physical And Mechanical Properties ◽

Fiber Direction ◽

Three Point Bending ◽

Compressive Stresses ◽

Cylindrical Samples

Guadua is a Colombian endemic type of grass belonging to the bamboo family. It can be considered an alternative construction material due to its physical and mechanical properties, as well as a sustainable source of timber due to its fast growing process and high availability in tropical countries. The Guadua is composed by the stem petiole or lower part, the stem base, and the stem. In turn, the stem is divided into sections separated by diaphragms that form knots, called culms. The distance between knots and the structure of the longitudinal fibers in the culms depend on the age of the plant. This implies a difficulty when determining the mechanical properties of the stem, since there are not specific standards for this purpose. In this work the mechanical properties of young samples of Angustifolia Kunt and Rayada Amarilla Guadua, of around 6 years of growth, were characterized. To account for the natural variability introduced by the presence of diaphragms, cylindrical and prismatic samples were extracted without knot, with one knot in the middle, and with one knot at each end. Cylindrical samples were used to measure compressive strength parallel to the fiber direction, while prismatic samples were used to measure tensile strength also parallel to the fiber direction and flexural strength by three point bending. Methodologies from conventional construction materials were adapted for this purpose. The obtained results allowed concluding that the Guadua samples present different mechanical properties depending on the position of the knots. Samples with a knot in the middle are more resistant to compressive stresses, while the samples without knot are more resistant to flexural and traction stresses. The samples with one knot at each end presented a more balanced behavior, being efficient when exposed to compression, traction and flexural stresses.

Download Full-text

Characteristics of Medium Density Fiberboards for Furniture Production and Interior Application

South East European Journal of Architecture and Design ◽

10.3889/seejad.2016.10013 ◽

2016 ◽

Vol 2016 ◽

pp. 1-5 ◽

Cited By ~ 1

Author(s):

Violeta Jakimovska Popovska ◽

Borche Iliev ◽

Ivo Spiroski

Keyword(s):

Mechanical Properties ◽

Physical And Mechanical Properties ◽

High Humidity ◽

Medium Density ◽

Production Sector ◽

Republic Of Macedonia ◽

Dry Conditions ◽

The Republic ◽

End Use

BACKGROUND: The paper analyzes the properties of medium density fiberboards (MDF) intended for furniture production and interior application. Because MDF panels are one of the mostly used wood-based panels in furniture production sector in the Republic of Macedonia it is important to know and understand their basic physical and mechanical properties. AIM: For better understanding of MDF panels and their proper end use by the furniture constructors and designers, physical and mechanical properties of MDF panels present in the market are tested.MATERIALS AND METHODS: Commercially produced MDF panels taken from one company from wood-based panel market were tested. Evaluation of the quality of the panels was made on the basis of the obtained results for the physical and mechanical properties of the panels. Properties of MDF were tested according to the national MKS standards and European norms.RESULTS: Tested MDF panels present on our market are characterized by good physical and mechanical properties that meet the requirements of the standards for MDF for use in dry conditions including furniture production and interior applications.CONCLUSIONS: It is recommended to avoid application of these MDF panels in high humidity conditions for a longer exploitation period. For this kind of applications, such as bathroom areas, the furniture constructors and interior designers should consider use of MDF.H type of panel for application in high humidity conditions, which will provide good dimensional stability of the products during whole exploitation period.

Download Full-text

Size Effect of Core Strands on the Major Physical and Mechanical Properties of Oriented Strand Boards from Fast Growing Tropical Species

10.5772/intechopen.99953 ◽

2021 ◽

Author(s):

Wan Mohd Nazri Wan Abdul Rahman ◽

Nur Sakinah Mohamed Tamat ◽

Nor Yuziah Mohd Yunus ◽

Jamaludin Kasim

Keyword(s):

Mechanical Properties ◽

Physical And Mechanical Properties ◽

Major Axis ◽

Resin Content ◽

Tropical Species ◽

Thickness Swelling ◽

Bending Properties ◽

Board Density ◽

Fast Growing ◽

The Face

Oriented strand board (OSB) is generally used for sheathing in residential walls, floors, and roofs. Because of its low pricing and utilisation of tiny diameter logs from fast-growing trees and thinning logs as raw materials, OSB is anticipated to gain popularity. In chapter, board properties of OSB using smaller strand size of Leucaena leucocephala as core layer had been studied. Small strand size of S3 (length = 75 mm, width = 3.2 to 6.3 mm) was located in the middle layer of the board while bigger strand sizes of S1 (length = 75 mm, width = 12.7 to 19.0 mm) and S2 (length = 75 mm, width = 6.3 to 12.7 mm) were located at the face and back layers. Utilization of smaller strands (S3) in the middle layers may yield boards that have better physical and mechanical properties. Except for MOR in the minor axis, board density and resin content were shown to have a substantial impact on physical and mechanical properties. Except for MOR in the major axis, strand size had little affected on physical and mechanical properties. The effects of board density on mechanical properties were discovered to affect significantly different. With a positive correlation, board density had a significant effect on thickness swelling. Between S1+S3 and S2+S3 strand size, there is no significant effect on bending properties, internal bond strength and thickness swelling. The effect of resin content on bending properties revealed a significant difference of MOR in major axis, as well as MOE values in both major and minor axes. Even when the resin content was as low as 5%, all treatments of OSB passed the general requirement of general purpose OSB.

Download Full-text

ORGANO-INORGANIC BINDERS FOR REPAIR AND RESTORATION OF TOWER TYPE HISTORY AND CULTURE MONUMENTS

10.34708/gstou.conf..2021.15.72.030 ◽

2021 ◽

Author(s):

С.Г. Шеина ◽

Д. К-С. Батаев ◽

С-А. Ю. Муртазаев ◽

П.Д. Батаева

Keyword(s):

Mechanical Properties ◽

Cultural Heritage ◽

Physical And Mechanical Properties ◽

Close Similarity ◽

Practical Application ◽

The Republic ◽

Cultural Heritage Objects ◽

Cultural Monuments

В статье делается обзор разработанных органо-неорганических составов растворов каменной кладки стен старинных башенных и некропольных строений Чеченской Республики и Республики Ингушетия. Отмечена перспективность практического применения органо-неорганических вяжущих для ремонта и реставрации памятников истории и культуры, благодаря близкому сходству разработанных составов «материнскому», за счет чего они более эффективны и способствуют повышению качества и долговечности. Исходя из анализа физико-механических свойств раствора для каменной кладки стен объектов культурного наследия рекомендованы три состава. The article provides an overview of the developed organic-inorganic compositions of masonry solutions for the walls of ancient tower and necropolis structures of the Chechen Republic and the Republic of Ingushetia. The prospects of the practical application of organic-inorganic binders for the repair and restoration of historical and cultural monuments are noted, due to the close similarity of the developed compositions to the "mother", due to which they are more effective and contribute to improving the quality and durability. Based on the analysis of the physical and mechanical properties of the mortar for the masonry of the walls of cultural heritage objects, three compositions are recommended.

Download Full-text

Design and Fabrication of Thermoplastic Moulds for Manufacturing CFRP Composite Impeller Blades

Materiale Plastice ◽

10.37358/mp.20.1.5338 ◽

2020 ◽

Vol 57 (1) ◽

pp. 290-298

Author(s):

Sorin Draghici ◽

Ionut Sebastian Vintila ◽

Radu Mihalache ◽

Horia Alexandru Petrescu ◽

Catalin Stelian Tuta ◽

...

Keyword(s):

Mechanical Properties ◽

Surface Quality ◽

Mechanical Characterization ◽

Physical And Mechanical Properties ◽

Full Scale ◽

Composite Processing ◽

Good Surface ◽

Hardness Tests ◽

Cfrp Composite ◽

3D Printed

The main objective of this study was to investigate thermoplastic materials design and fabrication processes for manufacturing composite impeller blades. Polyurethane (Necuron) and ABS (3D printed) thermoplastics were chosen due to their good mechanical properties, tooling applications, easy manufacturing and lifetime. For both thermoplastics, workability and hardness tests were performed, as well as microstructural and mechanical characterization evaluating their physical and mechanical properties. A 1:2.5 scale mould was designed and milled from Necuron N651 and N1001 and used for manufacturing of 1:2.5 scale composite impeller blades. Also, 1:1 scale ABS mould components were 3D printed and used to manufacture full scale composite impeller blades. All composite impeller presented good surface quality and tolerances with respect to CAD design, thus answering to requirements related to composite processing

Download Full-text

ESTIMATION OF BASIC PHYSICAL AND MECHANICAL PROPERTIES OF COMPOSITE MATERIALS FOR THE RESTORATION OF TEETH BY THE DIRECT METHOD WITH A COMBINATION OF MULTIPLE LAYERS OF COMPOSITES WITH DIFFERENT CONSISTENCY PASTES

Российский стоматологический журнал ◽

10.18821/1728-2802-2017-21-3-132-135 ◽

2017 ◽

Vol 21 (3) ◽

pp. 132-135

Author(s):

Anna Vladimirovna Starodubova ◽

Yu. A Vinnichenko ◽

I. Ya Poyurovskaya ◽

F. S Rusanov

Keyword(s):

Mechanical Properties ◽

Composite Materials ◽

Laboratory Test ◽

Polymer Composites ◽

Direct Method ◽

Physical And Mechanical Properties ◽

Adhesion Properties

The article investigated the strength and adhesion properties of polymer composites with different consistency pastes using deposition layering them in a laboratory test.

Download Full-text

Case Study of Anatomy, Physical and Mechanical Properties of the Sapwood and Heartwood of Random Tree Platycladus orientalis (L.) Franco from South-Eastern Poland

Forests ◽

10.3390/f12070925 ◽

2021 ◽

Vol 12 (7) ◽

pp. 925

Author(s):

Agnieszka Laskowska ◽

Karolina Majewska ◽

Paweł Kozakiewicz ◽

Mariusz Mamiński ◽

Grzegorz Bryk

Keyword(s):

Mechanical Properties ◽

Modulus Of Elasticity ◽

Bending Strength ◽

Physical And Mechanical Properties ◽

Tangential Direction ◽

Ultrasonic Waves ◽

Microscopic Structure ◽

Platycladus Orientalis ◽

Helical Thickenings

Oriental arborvitae is not fully characterized in terms of its microscopic structure or physical or mechanical properties. Moreover, there is a lot of contradictory information in the literature about oriental arborvitae, especially in terms of microscopic structure. Therefore, the sapwood (S) and heartwood (H) of Platycladus orientalis (L.) Franco from Central Europe were subjected to examinations. The presence of helical thickenings was found in earlywood tracheids (E). Latewood tracheids (L) were characterized by a similar thickness of radial and tangential walls and a similar diameter in the tangential direction in the sapwood and heartwood zones. In the case of earlywood tracheids, such a similarity was found only in the thickness of the tangential walls. The volume swelling (VS) of sapwood and heartwood after reaching maximum moisture content (MMC) was 12.8% (±0.5%) and 11.2% (±0.5%), respectively. The average velocity of ultrasonic waves along the fibers (υ) for a frequency of 40 kHz was about 6% lower in the heartwood zone than in the sapwood zone. The dynamic modulus of elasticity (MOED) was about 8% lower in the heartwood zone than in the sapwood zone. These differences, both in the case of υ and MOED, were statistically significant. However, no statistically significant differences were found for the static bending strength (MOR, approx. 90 MPa), modulus of elasticity at static bending (MOE, approx. 4800 MPa), or compression strength parallel to the grain (CS, approx. 47 MPa) in relation to the wood zone (sapwood, heartwood).

Download Full-text

Thermal Transmittance, Dimensional Stability, and Mechanical Properties of a Three-Layer Laminated Wood Made from Fir and Meranti and Its Potential Application for Wood-Frame Windows

Coatings ◽

10.3390/coatings11030304 ◽

2021 ◽

Vol 11 (3) ◽

pp. 304

Author(s):

Dimitrios Koutsianitis ◽

Konstantinos Ninikas ◽

Andromachi Mitani ◽

George Ntalos ◽

Nikolakakos Miltiadis ◽

...

Keyword(s):

Mechanical Properties ◽

Dimensional Stability ◽

Potential Application ◽

Physical And Mechanical Properties ◽

Solid Wood ◽

Manufacturing Cost ◽

Bending Properties ◽

Renewable Materials ◽

Thermal Transmittance ◽

Wood Frame

The aim of this paper was to investigate the physical (thermal transmittance and dimensional stability) and mechanical properties of two types of three layer laminated wood made from fir and meranti; fir in surface layers and meranti in core (FMF) and vice versa (MFM) and to examine its potential application for wood-frame windows. An additional objective was to compare the properties of the laminated wood with those of solid wood, namely meranti and fir. Both types of laminated wood had by far substantial lower bending properties than solid wood. MFM laminated wood performed better than the FMF as far as the physical and mechanical properties are concerned. Water absorption and thickness swelling of MFM laminated wood were substantially lower than those of the FMF type, and all the differences were statistically significant. Longitudinal width swelling, and bending properties of MFM laminated wood were higher than those of FMF but these differences were not statistically significant. The thermal transmittance (rate of the heat transferred) of the FMF window is 13.3% better (less) compared to the MFM window. The main reason for this is believed to be the lower overall density of the FMF window, which also makes it more competitive as a result of the reduced manufacturing cost since fir is less expensive compared tomeranti. It was concluded that wood-frame windows can be successfully made from these types of laminated wood, employing therefore easily renewable materials, with low environmental impact, recyclable and manageable in the medium term.

Download Full-text

Mechanical Properties of Sandstone using non-Destructive Method

Записки Горного института ◽

10.31897/pmi.2020.1.113 ◽

2020 ◽

Vol 241 ◽

pp. 113

Author(s):

H. Rajaoalison ◽

A. Zlotkowski ◽

G. Rambolamanana

Keyword(s):

Mechanical Properties ◽

Physical And Mechanical Properties ◽

Ultrasonic Waves ◽

Effect Of Temperature ◽

Drilling Process ◽

Wellbore Instability ◽

S Waves ◽

Coefficient Corrélation ◽

Rock Parameters ◽

Non Destructive

The understanding of physical and mechanical properties of rock is considered as critical in drilling, geo-engineering, and construction applications. As an example, the awareness of these rock parameters contributes to avoid or minimizing instability around the wellbore while drilling. The laboratory experiment of understanding of these parameters can be done in two-different ways: static, where the sample subjects to destruction after the test and dynamic, known as non-destruction method. The non-destructive method using ultrasonic waves under a series of different stress conditions, starting from 7 to 56 MPa with incrementation of 7MPa, has been used in this paper in order to characterize the mechanical properties of dry Zbylutów sandstone at 20 and 80°C. The velocity of primary (P) and secondary (S) waves within these ranges has been recorded in order to understand the behavior of the mechanical properties. The results showed that the Young’s modulus, bulk modulus, shear modulus, and Lame’s constant of Zbylutów sandstone have a positive correlation with good coefficient correlation with the increased stress, while the Poisson’s ratio showed a negative correlation. Besides, the effect of temperature on the rock parameters is approved by the decrease of primary wave velocity in this two-different temperature range. Such results are necessary when preparing the appropriate mud weight for drilling process, which is related to wellbore instability.

Download Full-text