• Journal of the Korean Society for Precision Engineering
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• v.17 no.5
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• pp.63-69
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• 2000

The main target of this research is investigating the relations between mechanical properties and injection conditions, like injection pressure, packing pressure and packing time for various contents ratio of glass fiber and resin. In general idea, high injection pressure produces high strength of molded parts as a monotonic function. but it was revealed that high pressure does not make high strength directly through various experiments of injection molding. In this experiments, PA66 was selected as resin and Glass Fiber was selected as reinforcing fiber Fiber reinforcement was controlled, as 14%, 25%, 33%, 44% of total volume and packing pressure was divided 55%, 65%, 75%, 85% of reference pressure, i.e. 100% equal to 1400kgf/$\textrm{cm}^2$. Finally, tensile testing was executed for injected test specimen. Optimum results based on authors' experiments have been obtained under conditions of 25% and 33% of glass fiber contents. Tensile strength rather depends on the packing pressure and packing time than injection pressure. Especially almost equal value of tensile strength was obtained for various percentage of packing and injection pressure as 65%, 75% and 85% of reference pressure.

• Journal of the Korea Institute of Building Construction
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• v.8 no.5
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• pp.43-51
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• 2008

This study examines shear capacity performance and structural characteristics of reinforced concrete beam using carbon fiber sheet(CFS), g)ass fiber sheet(GFS), glass fiber steel plate(GSP) and carbon fiber bar CB) which are reinforcing materials for reinforced concrete beam in order to produce similar condition to repair and reinforce actual structure and aims to provide data available In designing and constructing reinforced concrete structures under the structural damage. This study obtains the following conclusions. After considering the shear experiment results. it was indicated that the CB reinforced test object was the best in the shear capacity improvement and ductility capacity as it was contained in the concrete and was all operated, Also, GFS reinforced test object indicated the reduced flexural capacity but good shear capacity. GSP reinforced test object had bigger reinforcing strength than other reinforcing test objects. On the other hand, it showed the lowest reinforcement effect as compared section thickness of reinforced material because it showed the bigger relativity a section thickness of reinforced material. If the adherence to the concrete is improved, it will seem to show bigger reinforcement effect.

• Korean Chemical Engineering Research
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• v.50 no.5
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• pp.894-899
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• 2012

In recent years, recycling process has come to be necessary for separating metals, glass fibers and polymer from WPCBs (waste printed circuit boards) due to an increasing amount of electronic device waste. In this study, dimethylformamide (DMF) and attrition mill reactor were used to separate the component such as metals, glass fiber and epoxy resin from WPCBs. Separation of glass fiber from WPCBs was carried out under stirring rates 300~600 revolution per minute (rpm) for 1~2 h as the various agitator. The recycled glass fibers (RGF) were analyzed by thermogravimetric analyzer (TGA) for degree of separation of epoxy resin in the WPCBs. The degree of separation of epoxy resin of WPCBs increased in attrition mill agitator as a mechanochemical process for recycling WPCBs. The RGF separated in the WPCBs was applied as a reinforcement in the RGF/unsaturated polyester composites to reuse as a reinforcement.

• The Journal of Advanced Prosthodontics
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• v.9 no.1
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• pp.22-30
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• 2017

PURPOSE. The aim of this study was to investigate the effect of reinforcing materials on the fracture resistances of glass fiber mesh- and Cr-Co metal mesh-reinforced maxillary complete dentures under fatigue loading. MATERIALS AND METHODS. Glass fiber mesh- and Cr-Co mesh-reinforced maxillary complete dentures were fabricated using silicone molds and acrylic resin. A control group was prepared with no reinforcement (n = 15 per group). After fatigue loading was applied using a chewing simulator, fracture resistance was measured by a universal testing machine. The fracture patterns were analyzed and the fractured surfaces were observed by scanning electron microscopy. RESULTS. After cyclic loading, none of the dentures showed cracks or fractures. During fracture resistance testing, all unreinforced dentures experienced complete fracture. The mesh-reinforced dentures primarily showed posterior framework fracture. Deformation of the all-metal framework caused the metal mesh-reinforced denture to exhibit the highest fracture resistance, followed by the glass fiber mesh-reinforced denture (P<.05) and the control group (P<.05). The glass fiber mesh-reinforced denture primarily maintained its original shape with unbroken fibers. River line pattern of the control group, dimples and interdendritic fractures of the metal mesh group, and radial fracture lines of the glass fiber group were observed on the fractured surfaces. CONCLUSION. The glass fiber mesh-reinforced denture exhibits a fracture resistance higher than that of the unreinforced denture, but lower than that of the metal mesh-reinforced denture because of the deformation of the metal mesh. The glass fiber mesh-reinforced denture maintains its shape even after fracture, indicating the possibility of easier repair.

• Journal of the Korean Wood Science and Technology
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• v.42 no.5
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• pp.571-578
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• 2014

As a way of developing wooden joint development, a glass fiber reinforced wood plate was manufactured to replace a steel plate. Also, the fracture toughness was evaluated. Through application to a cantilever-type specimen made of a column and a beam, the moment resistance performance was evaluated. For the fracture toughness specimen of the wood plate, 12 types were manufactured by varying the combination of a main member (veneer and plywood) and reinforcement (glass fiber sheet and glass fiber cloth). The results of the fracture toughness test indicated that the 5% yield load of the specimen using plywood was 18% higher than that of the specimen using veneer, and that the specimen reinforced by inserting glass fiber sheets between testing materials (Type-3-PS) had the highest average 5% yield load 4841 N. Thus, a moment resistance strength test was performed by applying Type-3-PS to a column-beam joint. The results of the test indicated that compared to the specimen using a steel plate and a drift pin (Type-A), the maximum moment ratio of the specimen using a glass fiber reinforced wood plate (Type-3-PS) and a drift pin (Type-B) was 0.79; and that a rupture occurred in the wood plate due to high stiffness of the drift pin. The maximum moment ratio of the specimen using a glass fiber reinforced wood plate (Type-3-PS) and a glass fiber reinforced wooden laminated pin (Type-C) was 0.67, which showed low performance. However, unlike Type-A, a ductile fracture occurred on Type-C, and the load gradually decreased even after the maximum moment.

• Proceedings of the Korea Concrete Institute Conference
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• 1997.10a
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• pp.609-614
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• 1997

Recently, many researchers have performed R&D about strengthening of R/C with steel plates, carbon fiber sheets. aramid fiber sheets and glass fiber sheets, and so on. However most of research were limited in study of flexural strengthening of R/C beams. This paper shows the results of an experimental study on shear reinforcement of deep beams using Glass Fiber Sheet in relation to shear-span ratio. strengthening orientation and anchorage. The results prove that shear failure is governed by reinforced orientation. adherence and anchorage. Additional anchorage of fibers does not only cause the improvement in the internal resistance, but also control the brittle shear failure of specimen after reaching the maximum load.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2005.06a
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• pp.1322-1325
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• 2005

The main objectives of this research work are to develop conductive glass fiber woven roving and carbon fiber unidirectional fabric composite materials and to determine their electromagnetic shielding effectiveness(EMSE). Epoxy is the matrix phase and glass, carbon fiber are the reinforcement phase of the composite material. Carbon black are incorporated as conductive fillers to provide the electromagnetic shielding properties of the composite material. The amount of carbon black in the composite material is varied by changing the carbon black composition, woven roving and unidirectional (fabric) structure. The EMSE of various fabric composites is measured in the frequency range from 300MHz to 800MHz. The variations of EMSE of woven roving and unidirectional composites with fabric structure, metal powder composite are described. Suitability of conductive fabric composites for electromagnetic shielding applications is also discussed.

• The Journal of Korean Academy of Prosthodontics
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• v.39 no.6
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• pp.589-598
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• 2001

The fracture of acrylic resin dentures remains an unsolved problem. Therefore, many investigations have been performed and various approaches to strengthening acrylic resin, for example, the reinforcement of heat-cured PMMA resin using glass fibers, have been suggested over the years. The aim of the present study was to investigate the effect of short glass fibers treated with silane coupling agent on the transverse strength of heat-polymerized PMMA denture base resin. To avoid fiber bunching and achieve even fiber distribution, glass fiber bundles were mixed with PMMA powder in conventional mixer whose blade was modified to be blunt. Composite of glass fiber($11{\mu}m$ diameter, 3mm & 6mm length, silane treated) and PMMA resin was made. Transverse strength and Young's modulus were estimated. Glass fibers were incorporated with 1%, 3%, 6% and 9% by weight. Plasticity and workability of dough was evaluated. Fracture surface of specimens was investigated by SEM. The results of this study were as follows 1. 6% and 9% incorporation of 3mm glass fibers in the PMMA resin enhanced the transverse strength of the test specimens(p<0.05). 2. 6% incorporation of 6mm glass fibers in the PMMA resin increased transverse strength, but 9% incorporation of it decreased transverse strength(p<0.05). 3. When more than 3% of 3mm glass fibers and more than 6% of 6mm glass fibers were incorporated, Young's modulus increased significantly(p<0.05). 4. Workability decreased gradually as the percentage of the fibers increased. 5. Workability decreased gradually as the length of the fibers increased. 6. In SEM and LM, there was no bunching of fibers and no shortening of fibers.

• Proceedings of the Korea Concrete Institute Conference
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• 1999.10a
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• pp.689-692
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• 1999

In recent years, FRP plates have been studied for flexural reinforcement of RC structures due to easy installation and good quality control. This study presents experimental results for the effectiveness of flexural reinforcement of the RC beams using thin CFRP and GFRP stripe made by the pultrusion process. For the selected FRP strips of various thicknesses and widths, it was demonstrated that both flexural strength and ductility were considerably increased with relatively easy installation when compared to the other methods used for the composite reinforcement.

• Journal of the Korean Geotechnical Society
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• v.20 no.1
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• pp.13-19
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• 2004

The major distress types in the domestic asphalt pavement are fatigue cracking, reflection cracking, thermal cracking, and rutting. To decrease the pavement distress by reinforcing asphalt pavement with reinforcement interlayer in geosynthetics to the traditional pavement systems can improve these problems. This study conducted laboratory test with asphalt pavement reinforced by glass fiber sheet to fix systematically geosynthetic asphalt pavement system. Laboratory tests like wheel tracking test and crack resistance test are conducted to analyze the controlling effect of glass fiber sheet on cracking and rutting of asphalt pavement.