1,721,097 research outputs found
Bending moment and shear force capacities of the T-type doweled furniture joints reinforced with different sizes of corner blocks
No full textBu çalışmada, T-tipi kavelalı tutkallı mobilya birleştirmelerinde, köşe destek elemanı boyutunun moment ve kesme kuvveti taşıma performansı üzerindeki etkileri incelenmiştir. Deney örnekleri, Doğu kayını (Fagus orientalis Lipsky) ve sarıçam (Pinus sylvestris L.) odunlarından hazırlanmıştır. Doğu kayını kavelalar ile polivinilasetat (PVAc) tutkalı kullanılarak birleştirilmiş deney örnekleri, 30x30x25 mm, 40x40x25 mm, 50x50x25 mm ve 60x60x25 mm ölçülerindeki köşe destek elemanları ile desteklenmiştir. 2 deney türü, 2 ağaç türü, 4 değişik boyutta köşe destek elemanı, kontrol örnekleri ve her örnekten 10 yineleme olmak üzere toplam 200 örnek hazırlanmış olup, eğilme ve kesme yükleri altında denenerek moment ve kesme kuvveti taşıma performansları belirlenmiştir. Ayrıca, köşe destek elemanı boyutu ile moment ve kesme performansı arasındaki ilişkiler incelenerek matematiksel modeller geliştirilmiştir. Böylece, mobilya tasarımcıları bu eşitlikleri kullanarak her bir ağaç türü için, köşe destek elemanı boyutuna göre moment ve kesme kuvveti değerlerini önceden tahmin edebileceklerdir. Deneyler sonucunda, Doğu kayınından hazırlanmış 60x60x25 mm ölçülerindeki köşe destek elemanlı örnekler hem moment, hem de kesme performansında en yüksek değerleri vermiştir.In this study, effects of the corner block dimensions on moment and shear force capacities for T-type glued doweled furniture joints were investigated. Specimens were prepared of Turkish beech (Fagus orientalis Lipsky) and Scotch pine (Pinus sylvestris L.) woods. The specimens jointed with beech dowels and polyvinylacetate (PVAc) adhesive were reinforced by the corner blocks measuring of 30x30x25 mm, 40x40x25 mm, 50x50x25 mm ve 60x60x25 mm. A total of 200 specimens included 2 test types, 2 wood species, 4 corner block dimensions, control specimens, and 10 replications for each were prepared and tested under static bending and shear loads, thus the moment and shear force bearing performances were determined. Furthermore, the mathematical models were developed by analyzing the relations between the corner block dimensions and moment and shear performances. Therefore, furniture designers could estimate the moments and shear forces for each wood species as a function of corner block dimension by utilizing these predictive expressions. At the end of the tests, the specimens prepared of beech and reinforced with 60x60x25 mm corner blocks gave the highest values for both moment and shear performances
Determination of the Strength of Various Sofa Frames with Finite Element Analysis
No full textWOS: 000420955600002In this study, the strength properties of glued-dowel joined sofa frames constructed of solid wood and wood based composite materials were investigated. Furthermore, the place of the stretcher was optimized in the side frame of the sofa. Scotch pine (Pinus Sylvestris Lipsky) and Turkish beech (Fagus Orientalis Lipsky) were used as solid wood materials. Oriented strandboard (OSB), okoume (Aucoumea klaineana pierre) plywood (PLY) and medium density fiberboard (MDF) were used as wood composites. Specimens were tested under static load according to the principles of TS 9215 by applying both seat and backrest loads which the sofa can be imposed upon in service. The finite element method was utilized for analyzing the sofa frames. As a result, it has been observed that the three dimensional structural analysis by means of the finite element method gives reasonable estimates of the overall strength performances of the sofa frames. Furthermore; it was concluded that the wood composite materials could be used instead of solid wood materials in the production of the frame construction furniture, especially in the upholstered seating furniture frames
Determinatıon of the dowel holding performance of some solid wood and wood composite materials
No full textBu çalışmada; bazı masif ve kompozit ağaç malzemelerin, kenardan ve yüzeyden kavela tutma performanslarının belirlenmesi amaçlanmıştır. Deneylerde ağaç malzemelerden Doğu kayını (Fagus orientalis Lipsky) ve sarıçam (Pinus sylvestris L.), kompozit ağaç malzemelerden ise okume (Aucoumea klaineana) kontrplak (OKP), yonga levha (YL), iki ayrı kalitede yönlendirilmiş yonga levha (OSB1, OSB2), orta yoğunlukta lif levha (MDF), sentetik reçinelerle kaplanmış yonga levha (SUNTALAM) ve lif levha (MDFLAM) kullanılmıştır. Kavelaların yapıştırılmasında polivinilasetat (PVAc) tutkalından yararlanılmıştır. 9 malzeme çeşidi (2 masif, 7 kompozit), 2 farklı kavela çapı, 3 kavela girme derinliği (etkili boyu) ve her örnekten 10 yineleme olacak şekilde toplam 660 kenardan çekme, 540 adet de yüzeyden çekme örneği hazırlanmış ve statik yük altında denenmiştir. Ayrıca, deney sonuçları sayısal formüller haline getirilerek mobilya tasarımcılarının kenardan ve yüzeyden kavela tutma performansını, her bir malzeme çeşidi için kavela çapı ve kavela etkili boyunun fonksiyonu olarak tahmin etmeleri amaçlanmıştır. Sonuçlar, elde edilen formüllerle, kenardan ve yüzeyden kavela tutma performansının mantıklı bir şekilde tahmin edilebildiğini göstermiştir.In this study, determination of the edge and face dowel holding performances of some wood and wood composite materials were aimed. Turkish beech (Fagus orientalis Lipsky) and Scotch pine (Pinus sylvestris L.) were selected as the wood materials while okoume (Aucoumea klaineana) plywood (OKP), particleboard (YL), two different quality of oriented strand boards (OSB1, OSB2), medium density fiberboard (MDF), particleboard surfaced with synthetic resin sheet (SUNTALAM) and medium density fiberboard surfaced with synthetic resin sheet (MDFLAM) were used as the wood composite materials in the tests. Polyvinylacetate (PVAc) adhesive was utilized for gluing of the dowels. A total of 660 specimens were prepared for edge withdrawal tests including 9 material types (2 solid woods, 7 wood composites), 2 different diameters of dowel, 3 dowel penetrations and 10 replications for each group, and 540 specimens were prepared for face withdrawal tests, and they were tested under static loads. Furthermore, results of the tests were incorporated into predictive expressions that allow furniture designers to estimate edge and face dowel withdrawal performances for each material as a function of diameter of dowel and their depth of penetration. Results showed that the expressions developed provide reasonable estimates of edge and face dowel holding performances
Effect of the number of screws and screw size on moment capacity of furniture corner joints in case construction
No full textWOS: 000257171500007Tests were carried out in order to determine the bending moment capacity of L-type glued-screwed coner joints constructed with multiple screws. 6 sizes of screws were used for assembling the specimens. 2, 3, and 4 screws were used in the joints of the specimens that have the same width. Specimens were prepared of 18-mm-thick particleboard (PB) and medium density fiber-board (MDF) with resin surfacing. The specimens were constructed with both screws and polyurethane adhesive. Specimens were tested under static compression and tension loads. Results have shown that the maximum moment capacity is obtained with the MDF specimens when the number of screws in the joints is 4. In both compression and tension tests, MDF corner joints were stronger than PB corner joints. Results of the tests also indicated that a screw corner joint becomes stronger as either screw diameter or screw length is increased. Screw length was found to have a greater effect on moment capacity than diameter. Furthermore, the average moment capacities of glued-screwed corner joints evaluated in this study in compression could be predicted by means of the expressions: CMPB = -81.59 + 16.09 X + 14.52 Y + 1.47 Z CMMDF = -173.9 + 29.07 X + 24.62 Y + 2.26 Z and in tension by means of the expressions: TMPB = -8.4 + 17.73 X + 44.55 Y + 1.32 Z TMMDF = -136.1 + 32.42 X + 17.25 Y + 2.2 Z where CMPB, CMMDF = moment capacities of PB and MDF joints, respectively, under compression load (Nm); TMPB, TMMDF = moment capacities of PB and MDF joints, respectively, under tension load (Nm); X = number of screws; Y = screw diameter (mm); Z = screw penetration (mm)
Dermination of some physical and mechanical properties of various wood and wood composite materials
No full textBu çalışmada, çeşitli masif ve kompozit ağaç malzemelerin mobilya mühendislik tasarımında gerekli olan bazı fiziksel ve mekanik özellikleri, ilgili standartlara göre belirlenmiştir. Deneylerde, masif ağaç malzeme olarak Doğu kayını (Fagus Orientalis Lipsky) ve sarıçam (Pinus Sylvestris Lipsky), kompozit ağaç malzeme olarak da okume (Aucoumea klaineana) kontrplak (OKP), orta yoğunlukta lif levha (MDF) ve yönlendirilmiş yonga levha (OSB) kullanılmıştır. Deney malzemelerinin, yoğunlukları ve rutubet oranları tespit edilmiş, mekanik özelliklerden de çekme, basınç, kesme dirençleri ile eğilme direnci ve eğilmede elastikiyet modülü değerleri belirlenmiştir. Ayrıca, literatürdeki bazı çalışmalarda kullanılmış olan emniyet katsayıları kullanılarak masif ve kompozit ağaç malzemeler için kabul edilebilir tasarım (emniyet) gerilmeleri değerleri hesaplanmış ve mobilya tasarımcılarının kullanımına sunulmuştur.In this study, some technical properties needed in engineering design of furniture of some solid wood and wood composite materials were determined according to related standards. Turkish beech (Fagus Orientalis Lipsky) and Scotch pine (Pinus Sylvestrıs Lipsky) were used as solid wood materials; while, okoume (Aucoumea klaineana) plywood, medium density fiberboard (MDF) and oriented strand board (OSB) were used as wood composites. Densities and moisture contents of the test materials were measured, and tensile strength, compression strength, shear strength, bending strength (MOR) and modulus of elasticity (MOE) values were obtained among the mechanical properties. Furthermore, allowable design (safety) stress values were calculated for solid wood and wood composite materials by utilizing safety factors used in some studies in the literature and presented for furniture designers
Determination of the strength performance of chair frames constructed of solid wood and wood composites
No full textWOS: 000239849600009In this study, the strength properties of glued-doweled and screw jointed chair frames constructed of solid wood and wood-based (composite) materials were investigated. Scotch pine (Pinus Syivestris Lipsky) and Turkish beech (Fagus Orientalis Lipsky) were used as solid wood materials. Oriented strandboard (OSB), okoume (Aucoumea klaineana) plywood (PLY) and medium density fiberboard (MDF) were used as wood composites. Specimens were tested under static load according to the principles of ISO/DIS 7174/1 (ISO 1988) by applying both seat and backrest loads, which can be imposed upon the chair in service. In addition, specimens were structurally analyzed via the finite element method (FEM). The results show that three-dimensional (3-D) structural analyses by means of FEM gives reasonable estimates of the overall strength performance of the chair frames. As a result of static tests, it was concluded that the wood composite materials could be used as an alternative to solid wood material. In addition, portable connection techniques provide many advantages for designers, producers, sellers, and users. Performance testing was proven to be an essential part of the design process. These tests allow discovery and observation of unexpected failures and provide useful insight into actual usage and failure conditions
Experimental and numerical analysis of mounting force of auxetic dowels for furniture joints
No full textLimited number of papers describe the practical use of auxetics in the wood and furniture sector. Only one paper describes the auxetic nails. None of them analyzed the impact of using auxetics on the strength of furniture joints. The aim of this investigation was to design and manufacture different kinds of auxetic dowels with corresponding muffs and experimentally, theoretically, and numerically analyze the minimum mounting forces, contact pressures, and friction coefficients of these dowels in particleboard. Firstly, auxetic properties of the dowels were numerically determined, and then obtained values were confirmed by real compression tests in order to be sure that the dowels had negative Poisson's ratios. All dowels were manufactured from polyamide (PA12) with 3D printing Selective Laser Sintering (SLS) technology. Static compression tests were carried out for obtaining the minimum mounting force needed to insert the dowel into the muff. Numerical analyses were performed by means of Abaqus/Explicit v6.14-2 software. Contact pressures and friction coefficients were also theoretically calculated and compared to the results of numerical analyses and real tests. At the end of the tests, the auxetic dowels gave lower mounting force values than the non-auxetic dowels. Mounting force values of dowels decreased as the dowel hole diameter and size of inclusions are increased. Furthermore, the contact pressures on the surface of the auxetic dowels were considerably lower than in the non-auxetic dowels. In conclusion, it could be said that the auxetic dowels could be utilized as an alternative fastener for the traditional furniture dowels. Therefore, withdrawal strength and corner joint tests of the auxetic dowels should be investigated in future studies. © 2020 The Author(s)Ministerstwo Nauki i Szkolnictwa Wy?szegoThe paper was financed also within the framework of the Ministry of Science and Higher Education programme “Regional Initiative of Excellence” in years 2019-2022, Project No. 005/RID/2018/19. This study was also supported by Scientific and Technological Research Council of Turkey (TUBITAK) under the Science Fellowships and Grant Programs with the application no. 1059B191800913. Part of the computations was performed using computers of the Poznan Supercomputing and Networking Center
Determination of the strength of the ready to assemble sofa frames with finite element analysis
No full textBu çalışmada, ağaç ve ağaç esaslı (kompozit) malzemelerden tutkalsız-vidalı (demonte) olarak üretilmiş koltuk iskeletlerinin mukavemet özellikleri araştırılmıştır. Ayrıca, koltuk yan düzlem çerçevesinde, ara kayıtın yeri optimize edilmiştir. Masif ağaç malzeme olarak, I. sınıf sarıçam (Pinus Sylvestrıs L.) ve Doğu kayını (Fagus Orientalis L.), odun kompozitlerinden ise, yönlendirilmiş yonga levha (OSB), okume (Aucoumea klaineana pierre) kontrplak (PLY) ve orta yoğunlukta lif levha (MDF) kullanılmıştır. Koltuk iskeletleri kullanım esnasında maruz kalabilecekleri muhtemel yükleme biçimine göre TS 9215 de belirtilen kurallara uyularak statik oturma ve arkalık yüklemeleri ile denenmiştir. Koltuk iskeletlerinin yapısal çözümü için sonlu elemanlar analizi (Finite Element Analysis) yöntemi kullanılmıştır. Sonuç olarak, sonlu elemanlar yöntemi ile yapılan üç boyutlu yapısal analizler koltukların genel performansı açısından uygun değerler vermiştir. Ayrıca, sökülür-takılır birleştirme tekniklerinin tasarım, üretim ve kullanımda esneklik sağlayabileceği, oturma mobilyası sektöründe odun kompozitlerinin ağaç malzemeye alternatif olarak, özellikle kapalı döşeme gerektiren koltuk ve kanepelerde kullanılabileceği sonucuna varılmıştır.In this study, the strength properties of screwed-without glue (demonte) jointed sofa frames constructed of solid wood and wood based (composite) materials were investigated. Furthermore, place of the stretcher was optimized in the side frame of the sofa. First lass Scotch pine (Pinus Sylvestrıs Lipsky) and Turkish beech (Fagus Orientalis Lipsky) were used as solid wood materials. Oriented strandboard (OSB), okoume (Aucoumea klaineana) plywood and medium density fiberboard (MDF) were used as wood composites. Specimens were tested under static load according to the principles of TS 9215 by applying both seat and backrest loads which the sofa can be imposed upon in service. Finite element analysis method were utilized for structural analyzing the sofa frames. According to results, it has been observed that the three dimensional structural analysis by means of finite element method gives reasonable estimates of the overall strength performances of the sofa frames. As a result of the tests, it was concluded that the wood composite materials could be used instead of solid wood material, and portable connection techniques that provide many advantage for designers, producers, users and seller could be used in the production of the frame construction furniture, especially in the upholstered furniture frames
Bending Strength of Screwed Corner Joints with Different Materials
No full textWOS: 000420953400003Tests were carried out in order to determine the bending strength with compression and tension force with and without glue in addition to screws on furniture corner joints in a construction case. The specimens were prepared with particleboard and medium density fiberboard (MDF) surfaced with a synthetic resin sheet. In the connection, two types of screws which have dimensions of 4/50 mm and 5/60 mm were used. For the glued joints, polyurethane Desmodur-VTKA adhesive was used. As a result of these tests it has been determined that the joints with glue are better than the ones without glue and the strength of fiberboard is better than particleboard
STRUCTURAL ANALYSES OF WOODEN CHAIRS BY FINITE ELEMENT METHOD (FEM) AND ASSESSMENT OF THE CYCLIC LOADING PERFORMANCE TN COMPARISON WITH ALLOWABLE DESIGN LOADS
No full textTests were carried out to investigate the cyclic loading performance of chairs constructed of Scotch pine (Pinus sylvestris) and Oriental beech (Fagus orientalis). Totally, 30 real size chairs were constructed and assembled with polyvinyl acetate adhesive. Chairs were tested under 3 cyclic loading directions; namely, front to back, back to front, and backrest according to American Library Association (ALA) specifications, and obtained loading performances of chairs were crosschecked with allowable design load levels. Additionally, specimens were analyzed as structures by using the finite element method in order to obtain axial, shear, and bending stresses acting on each member under loadings and compare these values with design stresses. As a result, it was concluded that finite element method analyses achieve reasonable estimates for strength performances and failure behaviors of chairs. Depending on allowable design loads by American Library Association; chairs constructed of beech could meet the medium service for front to back and back to front loading, while heavy service for backrest loading. In the case of pine chairs; they could meet the medium service for front to back and back to front loading, while light service for backrest loading.Türkiye Bilimsel ve Teknolojik Araştirma Kurumu - 216O013
Muğla Sıtkı Koçman University Scientific Research Project Office with the project number - 17/11
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