Physics and Mechanical Wood
Jafar Eskandari; Amir sohil Pirayeshfar; Mohammad mehdi Jalili; Sayed yahya Mosavi; Mehran Rohnia
Abstract
In this study, three composites (Carbon fiber- Polyester resin, Glass fiber-Polyester resin and Hemp fiber-Polyester resin) are designed as a substitute for the wood in music instruments and their acoustic properties such as elastic modulus, acoustic coefficient, and acoustic coefficient efficiency are ...
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In this study, three composites (Carbon fiber- Polyester resin, Glass fiber-Polyester resin and Hemp fiber-Polyester resin) are designed as a substitute for the wood in music instruments and their acoustic properties such as elastic modulus, acoustic coefficient, and acoustic coefficient efficiency are investigated. For better evaluation of the results, two wood specimens from Cupressus arizonica and Morus Alba trees (which are using in many acoustic applications) were chosen and analyzed as control samples. The results show that the resultant composites possess essential acoustic and vibrational properties so that the result for Carbon fiber-Polyester composite exhibits tremendous acoustic properties than wood samples did. In this paper, the water absorption of resultant composites and wood samples were also measured. The results demonstrate that composites specimens could resist against humidity much better than wood samples.
Management and Economics wood
Alireza Mohammadi; Taghi Tabarsa; Mohammad Tasoji
Abstract
In this paper effect of static densification of treated paulownia on relationship between strength properties and density was investigated. Specimens were steamed at 130 and 170oc and immediately were compressed to 35% and 45% of their original thickness in radial direction. Mechanical properties such ...
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In this paper effect of static densification of treated paulownia on relationship between strength properties and density was investigated. Specimens were steamed at 130 and 170oc and immediately were compressed to 35% and 45% of their original thickness in radial direction. Mechanical properties such as bending strength, brinell surface hardness and compression strength in axial and radial direction were determined for non-densified and densified wood. Indexes of density, strength, quality and strength potential were calculated to study the relationship between strength and density. The results show that the density index and strength index and also strengths significantly increased with increase in densification but strength potential indexes decreased. Steam treatment at 130oc had a slight positive effect on the strengths and strength potential indexes as effect of softening the wood but the strength potential indexes and strengths decreased due to treatment of wood at 170oc. Generally, strength potential indexes of all tested mechanical properties show that strength of densified paulownia was lower compared to what had expected for non-densified paulownia from increasing density, which in turn demonstrate the cell walls were negatively affected by compression. Axial compression strength and brinell hardness were slightly affected by densification.
Physics and anatomy
Jamail Visi; Ghanbar Ebrahimi; Mohssen Bahmani
Abstract
The aim of this study was investigating the parameters of mortise and tenon joint made out of beech and hornbeam and develop formula to estimate ultimate bending strength. Mortis and tenon joint, one of the joints type, in placed in both form of corner and cross. In furniture industry, Mortis and ...
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The aim of this study was investigating the parameters of mortise and tenon joint made out of beech and hornbeam and develop formula to estimate ultimate bending strength. Mortis and tenon joint, one of the joints type, in placed in both form of corner and cross. In furniture industry, Mortis and tenon joint is widely used, because of its low cost and easy utilization. In this study, the effects of tenon height 2.5 ,3.5 and 5 cm, shoulder width 0/125, 0/25 and 0/375 cm on the resistance of Mortis and tenon against the ultimate bending strength were investigated. The results showed that the highest ultimate bending strength of Mortis and tenon in hornbeam possessed to the 5 cm tenon height and 0/25 shoulder width. Finally, it was found that the ultimate bending strength () of the joint could be predicted by means of the formula , where ultimate bending strength , is shear strength of the wood, = rail rail, tenon height, shoulder width factor, adhesive factor, tenon fit factor
Physics and Mechanical Wood
Morteza Mostafazadeh mrznaki; Saeid kazemi najafi; Majid Chaharmahali; Reza Hajihassani
Abstract
In study, the influence of flour content and immersion time in water on the creep behavior of composites made from mixes PB (Particle Board) and MDF (Medium Density Fiber Board) flour and high density polyethylene (HDPE) waste and was investigated. Mixing was done by a twin screw extruder and the sample ...
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In study, the influence of flour content and immersion time in water on the creep behavior of composites made from mixes PB (Particle Board) and MDF (Medium Density Fiber Board) flour and high density polyethylene (HDPE) waste and was investigated. Mixing was done by a twin screw extruder and the sample was manufactured by flat hot press. Firstly, the modulus of elasticity and bending strength of various mixes PB and MDF flour-polyethylene composites (WPCS) were measured before performing the creep test.It was shown that the modulus of WPCs increases with the increase in mixes PB and MDF flour content from 60% to 70% and then decreases as the flour content reaches to 80%. It is found that the bending strengths of WPCs significantly and linearly decreases with the increase in flour content from 60% to 80%. The results showed that, the creep strain decreases as the lignocellulosic flour level increases. Water absorption has negative effect on creep behavior of mixes PB and MDF flour/HDPE composites. For all filler contents, it can be seen that the creep strain increases when the immersion time increases.
Physics and Mechanical Wood
Morteza Khorami; Ahmad amin Khalili tabas; Amir Nourbakhsh
Abstract
Cement board without fibres has low flexural strength and fails in small strain. To solve this problem and enhance other characteristics, the fibres are applied. Asbestos fibres which have individual properties have been used for reinforcing cement composites since the early 20th century. However in ...
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Cement board without fibres has low flexural strength and fails in small strain. To solve this problem and enhance other characteristics, the fibres are applied. Asbestos fibres which have individual properties have been used for reinforcing cement composites since the early 20th century. However in this decade, most countries have been banned the use of asbestos fibres in construction industries, because of its effect on human healthy. Natural fibres are one of the suitable alternatives for cement board production that have a good compatibility with cement matrix. In this research, to recognize the flexural behaviour which is the one of the most important characteristics for cement board, many laboratory samples have been made by three kinds of fibres and tested. These fibres obtained from agricultural wastes such as bagasse, wheat and eucalyptus. The scanning Electronic Microscopic studies were carried out to clarify the microstructures of composites. The results show that among the all types of fibres, bagasse has the most effect on increasing the flexural strength capacity for cement composite boards.
Management and Economics wood
Sayed hamzeh Sadadt nezhad; Mehdi Tajvidi; Hossein Usefi
Abstract
In this study beech wood steamed specimens were compressed longitudinally to bulk cell wall at three levels of 0, 10 and 15 percent relative to their original length, and some mechanical properties including MOE, MOR, E-value, tensile strength, and tensile strain were measured. The results have shown ...
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In this study beech wood steamed specimens were compressed longitudinally to bulk cell wall at three levels of 0, 10 and 15 percent relative to their original length, and some mechanical properties including MOE, MOR, E-value, tensile strength, and tensile strain were measured. The results have shown that MOE, MOR and E-value as well as strength of specimens decrease with increasing compression but their tensile strain and work at maximum load increase.
Physics and anatomy
Fardad Golbabaei; Ghanbar Ebrahimi; Abolfazl Kargarfard; Abbas Fakhryan roghani
Abstract
Oak (Quercus castaneafolia C.A. Mey) is one of the most important broadleaf species in the Caspian Forests of Iran. The wood of oak is highly appreciated in domestic wood industries especially furniture industry.
In this study which is a part of the extensive surveying project of the main wood engineering ...
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Oak (Quercus castaneafolia C.A. Mey) is one of the most important broadleaf species in the Caspian Forests of Iran. The wood of oak is highly appreciated in domestic wood industries especially furniture industry.
In this study which is a part of the extensive surveying project of the main wood engineering properties of Iranian woods, the natural variations of strength and related properties of two trees of about 70 years old from Shafarod Forests in Gilan province were investigated.
The properties were determined from tests on small clear specimens in the green and dry conditions following the ASTM Standard. The mechanical and physical properties studied include: stress at elastic limits, modulus of rupture, modulus of elasticity and modulus of elasticity in static bending; shear parallel to grain, maximum crushing strength, fiber stress at proportional limit and modulus of elasticity in compression parallel to grain; compression perpendicular to grain and specific gravity.
The results of statistical analysis showed that the mechanical strength of the wood was found to be affected by percentage of moisture content of wood specimens, height of sample tree and to some extend by geographical; cal direction.
Physics and Mechanical Wood
Habib Nori; Ahmad Jahan latibari; mohammad ghofrani
Abstract
Poplar trees are classified as a fast growth trees and because of short rotation period, and suitable technical properties, are considered by pulp and paper making industries. In this study, physical and anatomical properties and pulp and paper of three colons of poplar trees, populous Alba. L. colon ...
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Poplar trees are classified as a fast growth trees and because of short rotation period, and suitable technical properties, are considered by pulp and paper making industries. In this study, physical and anatomical properties and pulp and paper of three colons of poplar trees, populous Alba. L. colon 44.9, populous deltoids 69.55, and populous euramerican are investigated. The average fiber length of these three colons were 0.854, 1.148, 1.08 mm. respectively and their average dry specific gravity were 0.386, 0461, and 0.341 g/cm3, and also their average cellulose content were 50.5, 51.5, and 49.5 percent.For Kraft process cooking of the mentioned colons, three cooking time, 1, 2, and 3 hours, 17°C cooking heat, 25% sulfidity, and active alkali at 3 levels, 15, 17.5, and 20% were used. The results show that p. alba, colon 44.9, and p. deltoids colon 69.55 with using 20% A.A and 3 hours cooking time have 53% yield and 18 kappa number.
Physics and Mechanical Wood
Shamohammad Amiri
Abstract
Anatomical, chemical and pulping characteristics of Cotton stalk as a nonwood material.Fiber length, fiber diameter, lemun and cell wall thickness were measured at 24.47, 16.43 and 4.02 mn respectively. Paper making coefficients were also calculated coefficient, flexibility coefficient and ranckl ...
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Anatomical, chemical and pulping characteristics of Cotton stalk as a nonwood material.Fiber length, fiber diameter, lemun and cell wall thickness were measured at 24.47, 16.43 and 4.02 mn respectively. Paper making coefficients were also calculated coefficient, flexibility coefficient and ranckl coefficient were calculated at 34.28, 67.14 and 48.93 respectively.Chemical composition of cotton stalk was determined at 47.83%cellulose, 21.66% lignin, 2.13% alcohol-acetone extractives and 2.83% ash.Soda pulping at following variables was investigated. Three levels, of cooking temperature (140, 160 and 180 degree Celsius), three cooking time (30, 40 and 50 minutes) and raw material condition (normal and debarked stalks). Active alkali of 20% (based on NaOH) and liquor to wood ratio of 5: 1 were kept constant for all soda cooks. The optimum combination of variables160 degree Celsius I temperature, 40 minutes time and debarked raw material. The yield and kappa no. of pulp obtained at this cooking condition was 50.4% and 89.15 respectively.
Physics and Mechanical Wood
Ghanbar Ebrahimi; Hossein Mahjob; Saeid Kazemi najafi
Abstract
Ultrasonic wave speed was measured in the longitudinal direction of Basswood on the top and bottom surfaces and center of lumbers during kiln drying in 3 Kiln load programs with final dry bulb of 80oC and different relative humidities. On the surfaces, wave speed decreased rapidly with MC declining from ...
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Ultrasonic wave speed was measured in the longitudinal direction of Basswood on the top and bottom surfaces and center of lumbers during kiln drying in 3 Kiln load programs with final dry bulb of 80oC and different relative humidities. On the surfaces, wave speed decreased rapidly with MC declining from green to FSP, but from FSP down to 7% moisture content wave speed did increased slowly. In the center of lumber, with decreasing MC from green to FSP, wave speed increased slowly, but by reducing MC to 7%, wave speed was rapidly increased. 5% MC, on the three surface of lumber, wave speed had no drastic difference. Results indicated that ultrasonic wave speed and MC of wood show a parabolic relationship. Further, results have shown that measuring ultrasonic wave speed is an appropriate method to control kiln drying program for hardwood lumber
Physics and Mechanical Wood
Zoghali Syahipoor; Fardad Golbabaei
Abstract
In this study, in order to achieve sufficient accuracy both quality and quantity factors in two forestry plantanation of Picea abies using 100% statistics were used. In order to investigate wood quality, fiber length, density and mechanical properties, 4 thick cross section trees were selected and cut ...
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In this study, in order to achieve sufficient accuracy both quality and quantity factors in two forestry plantanation of Picea abies using 100% statistics were used. In order to investigate wood quality, fiber length, density and mechanical properties, 4 thick cross section trees were selected and cut in two area of Piseson at high 1450m. altitude and Syahkal at 650m. altitude. According to the results of measuring of diameter, height and average annual growth of the samples and comparison of different sites condition, it could be concluded that plantation of Picea abies is advantageous. Finally, the results show that in Piseson wood with low mechanical properties were produced. The average annual growth of wood in Piseson is 63mm. where as in syahkal is 60mm.
Physics and Mechanical Wood
Fardad Golbabaei; Amir Nourbakhsh; Abbas Fakhryan roghani; Shahrokh Falahdoost
Abstract
Beech (Fagus orientalis Lipsky L.) is one of the most important broadleaf species in the Caspian Forests of Iran. The wood of Beech is highly appreciated in domestic wood industries especially furniture industry. In this study which is a part of the extensive surveying project of the main wood engineering ...
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Beech (Fagus orientalis Lipsky L.) is one of the most important broadleaf species in the Caspian Forests of Iran. The wood of Beech is highly appreciated in domestic wood industries especially furniture industry. In this study which is a part of the extensive surveying project of the main wood engineering properties of Iranian woods, the natural variations of strength and related properties of three trees of about 75 years old from Sangdeh Forests in Mazandran province were investigated.The properties were determined from tests on small clear specimens in the green and dry conditions following the ASTM Standard. The mechanical and physical properties studied include: stress at elastic limits, modulus of rupture, modulus of elasticity and modulus of elasticity in static bending; shear parallel to grain, maximum crushing strength, fiber stress at proportional limit and modulus of elasticity in compression parallel to grain; compression perpendicular to grain and specific gravity.The results of statistical analysis showed that the mechanical strength of the wood was found to be affected by percentage of moisture conten of wood specimens, height of sample tree and to some extend by geographical; direction.
Physics and Mechanical Wood
Fardad Golbabaei; Amir Nourbakhsh; Abbas Fakhryan roghani; Shahrokh Falahdoost
Abstract
In this study physical and mechanical properties of Hornbeam wood (Carpinus betulus L.) grown at two different elevations of Golestan Forests located in the north east of Caspian Sea were investigated based on the ASTM Standard.Selected trees were cut from two different elevations, at different heights ...
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In this study physical and mechanical properties of Hornbeam wood (Carpinus betulus L.) grown at two different elevations of Golestan Forests located in the north east of Caspian Sea were investigated based on the ASTM Standard.Selected trees were cut from two different elevations, at different heights in the trunk, at 4 different geographical directions of the trunk and also 2 different moisture contents.The results of statistical analysis showed that properties of Hornbeam wood from this region were influenced by elevations and to the lessees extend by geographical direction of wood specimens and tree heights.
Physics and Mechanical Wood
Fardad Golbabaei; Abdolrahman Hosseinzadeh; Amir Nourbakhsh; Hossein Hosseinkhani; Abbas Fakhryan roghani
Abstract
In this study physical and mechanical properties of Hornbeam (Carpinus betulus L.) grown at three different elevations of Asalem Forests located at the north west of Gilan were investigated following the ASTM Standard. Sample trees were selected from 3 different elevations, at different height of trees, ...
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In this study physical and mechanical properties of Hornbeam (Carpinus betulus L.) grown at three different elevations of Asalem Forests located at the north west of Gilan were investigated following the ASTM Standard. Sample trees were selected from 3 different elevations, at different height of trees, at 4 different geographical directions of the stems and 2 different moisture contents.The results of statistical analysis revealed that properties of Hornbeam wood from this region was influenced by elevations and to the lessees extend to geographical direction of wood specimens and tree height.
Physics and Mechanical Wood
Abdolrahman Hosseinzadeh; Fardad Golbabaei; Amir Nourbakhsh; Hossein Hosseinkhani
Abstract
In this study physical and mechanical properties of Beech (Fagus orientalis Lipsky) grown at two different elevations of Asalem Forests located an the north west of Gilan were investigated following the ASTM Standard. Sample trees were selected from 2 different elevations, at different high of trees, ...
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In this study physical and mechanical properties of Beech (Fagus orientalis Lipsky) grown at two different elevations of Asalem Forests located an the north west of Gilan were investigated following the ASTM Standard. Sample trees were selected from 2 different elevations, at different high of trees, at 4 different geographical directions of the stems and 2 different moisture contents.The results of statistical analysis revealed that properties of Beech wood from this region was influenced by elevations and to the lessees extend to geographical direction of wood specimens and tree highs.
Management and Economics wood
Habibalah Arabtabar; Abdolrahman Hosseinzadeh; Ali Rezanezhad; Ghanbar Ebrahimi
Abstract
The economical importance of railroads and their development in Iran have been caused those annually 500000 wood sleepers to be required, if sleepers are to be maintained in suitable condition. However, the wood resources are also limited, specially producing roadbeds with high classes. For conservation ...
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The economical importance of railroads and their development in Iran have been caused those annually 500000 wood sleepers to be required, if sleepers are to be maintained in suitable condition. However, the wood resources are also limited, specially producing roadbeds with high classes. For conservation of natural resources (Forests) we need to use logs with lower classes as well. The process of lamination can permits manufacturing sleepers from small logs. Therefore, the manufacturing of two half laminated ties (interface vertical or horizontal) were lower. As in Iranian beech is usually used for manufacturing sleepers, in this study it was also utilized to make dowel-laminated sleepers. The results of this study showed that, the processes of impregnation of dowel-laminated sleepers with preservative (Creosote) and depth of its penetration were better established than in usual sleepers. Laboratory test indicated that modulus of elasticity of two half laminated - vertical sleepers was the same as the usual sleepers but this resistance in two half laminated - horizontal sleepers was decreased. Finally after five years exposure under extensive service, tests no failures in dowel-laminated sleepers especially in vertical shapes were observed.
Physics and anatomy
Abdolrahman Hosseinzadeh; Hossein Familian; Kamyar Salehi; Abbas Fakhryan roghani; Fardad Golbabaei; Habibalah Arabtabar; Nayeralsadat Sadraei
Abstract
Eight-nineteen-year-old trees from Eucalyptus intertexta from Sarab bahman experimental Plantation located 160 Km. South west of Shiraz were selected randomly and fell two from each of the four blocks. Form each tree, 10 cm. thick cross-sectional discs at several different heights (3 meters intervals) ...
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Eight-nineteen-year-old trees from Eucalyptus intertexta from Sarab bahman experimental Plantation located 160 Km. South west of Shiraz were selected randomly and fell two from each of the four blocks. Form each tree, 10 cm. thick cross-sectional discs at several different heights (3 meters intervals) were cut and together with remaining boles then transferred to the Alborz Research Center-Karaj for laboratory studies. The laboratory studies included determination of physical, anatomical and mechanical properties as well as chemical compositions of wood. The mechanical properties were evaluated on the ASTM methods for air-dry and green conditions. The following conclusions were drawn from this study:E. intertexta from one site in southern region of Iran has an average specific gravity of 0.86, fiber length of 0.71 mm, fiber diameter of 25.26 mm, lumen diameter of 4.04 mm, cell wall thickness 5.62 mm, cellulose content of 45.95; lignin 28.2; extractives soluble in alcohol - Banzen 4.28 and ash 0.62 percent.It was found that the mean values of modulus of rupture, modulus of elasticity and compression strength-parallel to grain tested at green condition were 74.21 MPa, 8454 MPa and 38.52 MPa and air-dried condition were 123.47 MPa, 14667 MPa and 77.99 MPa respectively. Data are also presented on other mechanical properties such as impact strength, nail withdrawal cleavage and etc.
Chemistry of wood
Abdolrahman Hosseinzadeh; Abbas Fakhryan roghani; Fardad Golbabaei; Nayeralsadat Sadraei
Abstract
Eight-nineteen-year-old trees from Eucalyptus camaldulensis from De- hnow experimental Plantation located 160 Km. South west of Shiraz were selected randomly and fell two from each of the four blocks. Form each tree, 10 cm. thick cross-sectional discs at several different heights (3 meters intervals) ...
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Eight-nineteen-year-old trees from Eucalyptus camaldulensis from De- hnow experimental Plantation located 160 Km. South west of Shiraz were selected randomly and fell two from each of the four blocks. Form each tree, 10 cm. thick cross-sectional discs at several different heights (3 meters intervals) were cut and together with remaining boles then transferred to the Alborz Research Center-Karaj for laboratory studies. The laboratory studies included determination of physical, anatomical and mechanical properties as well as chemical compositions of wood.The mechanical properties were evaluated on the ASTM methods for air-dry and green conditions. The following conclusions were drawn from this study:E. camaldulensis from one site in southern region of Iran has an average specific gravity of 0.806, Fiber length of 1.043 mm, fiber diameter of 15.38 mm, lumen diameter of 4.84 mm, cell wall thickness 5.29 mm, cellulose content of 42.5 percent. It was found that the mean values of modulus of rupture, modulus of elasticity and compression strength-parallel to grain tested at green condition were 81.19 MPa, 10887 MPa and 67.39 MPa respectively.Data are also presented on other mechanical properties such as impact strength, nail withdrawal cleavage and etc.
Physics and Mechanical Wood
Abdolrahman Hosseinzadeh; Nooshin Toghraie; Fardad Golbabaei
Abstract
To determine major engineering properties of Hornbeam wood (Carpinus betulus L.) in Vaisar region of Caspian Forests (North of Iran), adopting ASTM (D-143) Standard specifications, the matched small clear specimens were prepared. The test materials were derived from three randomly chosen trees. Mechanical ...
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To determine major engineering properties of Hornbeam wood (Carpinus betulus L.) in Vaisar region of Caspian Forests (North of Iran), adopting ASTM (D-143) Standard specifications, the matched small clear specimens were prepared. The test materials were derived from three randomly chosen trees. Mechanical and physical properties were measured on two moisture states: green and air - dried (at 12% moisture content).The influence of locations of specimens in the height of tree trunks and geographical directions were tested on target properties. From the results of this study it could be concluded that, there were no significant differences between the various heights and geographical directions from the pith for most of the properties investigated.Toughness was not influenced by moisture content. The average value of hardness of Hornbeam wood in transverse sections were the same as side_grain sections in green condition, but air-drying caused increasing the value of cross - sections about 30% The compression strength perpendicular r to the grain showed differences in wet and dry conditions.
