Connection plays an important role in structural components and end jointing is one of the most common connections in structural applications. This study was designed to investigate some mechanical properties （MOE an...Connection plays an important role in structural components and end jointing is one of the most common connections in structural applications. This study was designed to investigate some mechanical properties （MOE and MOR） of solid wood samples manufactured from poplar （Populus nigra）, joined together through end jointing. As well, we studied combinations of lumber manufactured from 10-mm veneer, using a polyvinyl acetate adhesive. The results show that non-jointed lumber （control samples） have better bending properties （MOE and MOR） than jointed specimens and lumber made from laminated layers. On the whole, side-by- side joints have a negative effect on the MOR and MOE of laminated products, which is more pronounced in the MOR. By increasing the number of joints, the properties of combination of three-ply, i.e., bending strength and modulus of elasticity, decreased.展开更多
In this research, a series of wood-based panels were produced by using wood chips [beech (Fagus Sylvatica L.) and Scotch pine (Pinus sylvestris L.)] as wastes of wood-working workshops and acrylic fibers as wastes of ...In this research, a series of wood-based panels were produced by using wood chips [beech (Fagus Sylvatica L.) and Scotch pine (Pinus sylvestris L.)] as wastes of wood-working workshops and acrylic fibers as wastes of textiles factory. Four kinds of different panels (Eltapan I, II, III and IV) were obtained by mixing these components in different composition (0%, 25% and 50%). Some physical and mechanical properties of the samples taken from these panels were determined in accordance with ASTM D1037-12 and ASTM-C 1113. The values were compared to properties of industrially produced chipboard. As a result, the textile fibers used as additive material reduced density, thermal conductivity and bending resistance of wood panel and increased dimensional stability of wood panel.展开更多
One of the alternative sustainable and green construction materials to concrete is timber. Timber is of numerous varieties, and this acts as a barrier to the extent of its usage, especially in structural application. ...One of the alternative sustainable and green construction materials to concrete is timber. Timber is of numerous varieties, and this acts as a barrier to the extent of its usage, especially in structural application. Despite many researches on wood’s mechanical and physical properties, only a few are geared toward the structural application of wood. The present work investigated the mechanical properties of five timber species;Gmelina arborea, Tectona grandis (Teak), Terminalia superba (Afara), Ayin (Anogeissus leiocarpus), and Acacia (Robinia pseudoacacia), to determine their suitability for constructing long-span roof trusses. These are available in the South Western part of Nigeria. Their mechanical properties;bending strength, compressive strength, shear strength, tensile strength, Modulus of Elasticity (MOE), Modulus of Rupture (MOR), and density, were determined in the laboratory. The results obtained showed that all the timber types, except Terminalia superba (Afara), have higher values of mechanical properties than the values that are obtainable for classes of strength D30 to class D70 in the British Code of Practice. It means these species are of higher quality than the stipulated strength classes in the British code. The results also show that the order of relevance of the species for structural design (or work) is Acacia (Robinia pseudoacacia), Ayin (Anogeissus leiocarpus), Gmelina Arborea, and Tectona grandis (Teak). Terminalia superba (Afara) is not recommended for structural works.展开更多
Compared with the undamaged Phyllostachys edulis,the wood mechanical properties of bended bamboo for 4-year-old by frost and snow were studied. It was shown that the wood mechanical properties of bended Phyllostachys ...Compared with the undamaged Phyllostachys edulis,the wood mechanical properties of bended bamboo for 4-year-old by frost and snow were studied. It was shown that the wood mechanical properties of bended Phyllostachys edulis were equivalent to or a little less than those of the undamaged bamboo. The bending strength(MOR) of moderately bended bamboo and the modulus of elasticity in static bending(MOE) of heavily bended bamboo were 125.8 MPa and 10 978.9 MPa respectively in the culm base,and compared with those of undamaged Phyllostachys edulis wood,the differences were significant. However,the other mechanical properties including tensile strength parallel to grain,compressive strength parallel to grain and shearing strength parallel to grain etc. Between bended and undamaged bamboo wood,the difference were not significant. The study results could provide data supports for the proper ways of rational cutting,process and utilization of bended Phyllostachys edulis wood.展开更多
文摘Connection plays an important role in structural components and end jointing is one of the most common connections in structural applications. This study was designed to investigate some mechanical properties （MOE and MOR） of solid wood samples manufactured from poplar （Populus nigra）, joined together through end jointing. As well, we studied combinations of lumber manufactured from 10-mm veneer, using a polyvinyl acetate adhesive. The results show that non-jointed lumber （control samples） have better bending properties （MOE and MOR） than jointed specimens and lumber made from laminated layers. On the whole, side-by- side joints have a negative effect on the MOR and MOE of laminated products, which is more pronounced in the MOR. By increasing the number of joints, the properties of combination of three-ply, i.e., bending strength and modulus of elasticity, decreased.
文摘In this research, a series of wood-based panels were produced by using wood chips [beech (Fagus Sylvatica L.) and Scotch pine (Pinus sylvestris L.)] as wastes of wood-working workshops and acrylic fibers as wastes of textiles factory. Four kinds of different panels (Eltapan I, II, III and IV) were obtained by mixing these components in different composition (0%, 25% and 50%). Some physical and mechanical properties of the samples taken from these panels were determined in accordance with ASTM D1037-12 and ASTM-C 1113. The values were compared to properties of industrially produced chipboard. As a result, the textile fibers used as additive material reduced density, thermal conductivity and bending resistance of wood panel and increased dimensional stability of wood panel.
文摘One of the alternative sustainable and green construction materials to concrete is timber. Timber is of numerous varieties, and this acts as a barrier to the extent of its usage, especially in structural application. Despite many researches on wood’s mechanical and physical properties, only a few are geared toward the structural application of wood. The present work investigated the mechanical properties of five timber species;Gmelina arborea, Tectona grandis (Teak), Terminalia superba (Afara), Ayin (Anogeissus leiocarpus), and Acacia (Robinia pseudoacacia), to determine their suitability for constructing long-span roof trusses. These are available in the South Western part of Nigeria. Their mechanical properties;bending strength, compressive strength, shear strength, tensile strength, Modulus of Elasticity (MOE), Modulus of Rupture (MOR), and density, were determined in the laboratory. The results obtained showed that all the timber types, except Terminalia superba (Afara), have higher values of mechanical properties than the values that are obtainable for classes of strength D30 to class D70 in the British Code of Practice. It means these species are of higher quality than the stipulated strength classes in the British code. The results also show that the order of relevance of the species for structural design (or work) is Acacia (Robinia pseudoacacia), Ayin (Anogeissus leiocarpus), Gmelina Arborea, and Tectona grandis (Teak). Terminalia superba (Afara) is not recommended for structural works.
文摘Compared with the undamaged Phyllostachys edulis,the wood mechanical properties of bended bamboo for 4-year-old by frost and snow were studied. It was shown that the wood mechanical properties of bended Phyllostachys edulis were equivalent to or a little less than those of the undamaged bamboo. The bending strength(MOR) of moderately bended bamboo and the modulus of elasticity in static bending(MOE) of heavily bended bamboo were 125.8 MPa and 10 978.9 MPa respectively in the culm base,and compared with those of undamaged Phyllostachys edulis wood,the differences were significant. However,the other mechanical properties including tensile strength parallel to grain,compressive strength parallel to grain and shearing strength parallel to grain etc. Between bended and undamaged bamboo wood,the difference were not significant. The study results could provide data supports for the proper ways of rational cutting,process and utilization of bended Phyllostachys edulis wood.
