PANTEA OMRANI; Hamideh Abdolzadeh; Mohsen Abedi
Abstract
Fiber Reinforced Polymer (FRP) has become one of the most popular methods in the reinforced, repair and rehabilitation of structure due to its ease of application and the special physical characteristics. Both destructive and nondestructive assessments have been used to test the characteristics and durability ...
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Fiber Reinforced Polymer (FRP) has become one of the most popular methods in the reinforced, repair and rehabilitation of structure due to its ease of application and the special physical characteristics. Both destructive and nondestructive assessments have been used to test the characteristics and durability of FRP in order to investigate the condition of the structure. The aim of this research was to investigate the structural performance of corner joint reinforced with fiber reinforced polymer (FRP) composite under diagonal tension load. Constructed joints from two wooden species of beech (Fagus orientalis) and fir (Abies alba), were reinforced with reinforced composites of one and two layer of carbon and glass fibers and then they were tested under diagonal tension load. The miter corner joints were made with wooden pin and polyvinyl acetate adhesive. The fibers lay-up was done manually. Epoxy resin was used as a polymeric matrix. Result of investigation indicated that use of beech wood in comparison with fir exhibited better results. In addition, glass fibers have shown better performance than carbon fiber as reinforcing agents. Inspection of diagonal tension specimens after failure have indicated that using of FRPs on the surfaces of L-shaped miter prevent joint opening, however, failure was occurred at the joint by increasing of load and vertical displacement and the general wood weakness in tension perpendicular to the grain and shear parallel to the grain at dowels site due to stress concentration. Also the results showed that the miter corner joint made with beech species and two layers of glass fibers had the highest stress carrying capacity.
Pantea Oimranin; Hamideh Abdolzadeh; Mohsen Abedi
Abstract
The aim of this study was investigation of the performance of mitered corner joints (L-shaped) reinforced by fibers reinforced polymer (FRP) at maximum stress area under diagonal compression loading. In This way, structural performance of constructed corner joints of two species of beech and fir reinforced ...
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The aim of this study was investigation of the performance of mitered corner joints (L-shaped) reinforced by fibers reinforced polymer (FRP) at maximum stress area under diagonal compression loading. In This way, structural performance of constructed corner joints of two species of beech and fir reinforced by fiber reinforced polymer at polymeric matrix of epoxy with one and two layer of carbon and glass fibers and were investigated. After construction of the mitered joints with wooden dowel and polyvinyl acetate adhesive, the joints were reinforced with FRP composites and then were subjected to diagonal compression loading. Results have indicated that reinforcing layers prevent joint opening, however, failure was occurred at the joint by peeling fibers from wood surface or members fracture near the joints by stress concentration. The results of variance analysis showed that the independent effect of species of joint members and numbers of fibers layer were significant at 95% confidence level. The results showed that use of beech wood in comparison with fir wood, composites reinforced by carbon fibers compared to glass fibers, as well as the use of two layers of fiber compared to 1 layer of fibers, exhibited better performance in constructed joints. The joints made with beech wood and reinforced with 2 layers of composites reinforced by carbon fibers showed the best performance under diagonal compression loading.
Pantea Omrani; Hamideh Abdolzadeh; Ali Adab
Abstract
The aim of this research was investigating the effect of fiber reinforced polymer (FRP) on the strength of T-shaped wooden joints under tension load. In this regard, T-shaped joints were constructed with beech and poplar species and were reinforced with 1 and 2 layer of carbon and glass fibers reinforced ...
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The aim of this research was investigating the effect of fiber reinforced polymer (FRP) on the strength of T-shaped wooden joints under tension load. In this regard, T-shaped joints were constructed with beech and poplar species and were reinforced with 1 and 2 layer of carbon and glass fibers reinforced epoxy and vinylester polymers of composite. Joint members were assembled by used of wooden dowels and polyvinyl acetate adhesive and then withdrawal resistance of reinforced joints were studied. Results of variance analysis showed that the independent effect of species of joint members, resin type and number of fiber layers at FRPs was significant at 5% level. Results have indicated that withdrawal resistance of joints constructed with beech species was more than the poplar species. The investigation of the effect of number of layers showed that the withdrawal resistance of the joints reinforced by two layers of carbon and glass fibers was more than one layer. Results of FRPs investigation indicated that use of epoxy matrix in comparison with vinyl ester matrix exhibited better results. In addition, carbon fibers have shown better performance than glass fiber as reinforcing agents. According to the results the best treatment was the joints of beech wood and reinforced by composites with epoxy matrix and reinforced with two layers of carbon fibers.
PANTEA OMRANI; Hadi maryami; Reza Eisapor
Abstract
Joints in furniture and wooden structures due to the highly sensitive bearing load are today one of the most important scientific topics. The most recent method proposed to build wooden joints in Europe and the United States is a method eco-friendly, without using any type of adhesive substance or connector, ...
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Joints in furniture and wooden structures due to the highly sensitive bearing load are today one of the most important scientific topics. The most recent method proposed to build wooden joints in Europe and the United States is a method eco-friendly, without using any type of adhesive substance or connector, called "wood welding". In the present study, the effect of diameter and dowel surface on the tensile strength of softwood joints (made with dowel) was investigated using two methods: wood welding and glue bonding. Polyvinyl acetate glue (PVA) for bonding, species Fir (Abies alba) for members joint and species Hornbeam (Carpinus betulus) for connector dowels were selected as fixed parameters. The structure of the welded surfaces was analyzed using scanning electron microscopy (SEM). The results of the tensile strength test showed that parameters of diameter and type of dowel surface have a significant effect on the tensile strength of softwood joints in both joint methods.
Mechanical conversion of wood and wooden fittings
PANTEA OMRANI; Reza Eisapor
Abstract
The insertion of dowels into solid wood for furniture has been used for centuries. Recently, this simple technology has been upgraded. The objective of the research was to evaluate and compare the tensile strength of the joints made of wood dowel through new method “wood welding” and classical ...
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The insertion of dowels into solid wood for furniture has been used for centuries. Recently, this simple technology has been upgraded. The objective of the research was to evaluate and compare the tensile strength of the joints made of wood dowel through new method “wood welding” and classical method “using of glue”. Variables included dowel joints method (welding joint and joint with glue), dowel diameter (10 and 12 mm) and dowel surface (smooth and grooved). Members joint and dowel wood were hornbeam species (Carpinus betulus) and the used glue was polyvinyl acetate (PVA). The results showed that the types of joints, diameter and surface dowel, have significant effect on the tensile strength, so that welded joints, dowel diameter 12 mm and dowel grooved surface has the most tensile strength to other samples. The results also showed that in all cases, the strengths of the joints made by welding was more than the joints made by PVA glue.
