• Proceedings of the Korean Institute of Building Construction Conference
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• 2019.05a
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• pp.65-66
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• 2019

In this study, flexural strength and impact resistance were evaluated to investigate the fiber length effect of amorphous metallic fiber. As a result, in the case of 30AFRCC, cutoff behavior due to excellent bonding performance by large specific surface area has greatly influence on the flexural and impact resistance performance. In the case of 15AFRCC, the bonding efficiency is relatively low, because the specific surface area is smaller than that of 30AFRCC and the number of fiber is large, so the effect of improving the flexural and impact resistance performance is smaller than that of 30AFRCC.

• Journal of the Korean Society of Safety
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• v.38 no.2
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• pp.1-7
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• 2023

Fiber-metal laminates (FMLs) and polymer matrix composites (PMCs) are formed in various ways. In particular, FMLs in which aluminum is laminated as a reinforced layer are widely used. Also, glass fiber-reinforced plastics (GFRPs) are generally applied as fiber laminates. The bonding interface layer between the aluminum and fiber laminate exhibits low strength when subjected to hot press fabrication in the event of delamination fracture at the interface. This study presents a simple method for strengthening the interface bonding between the aluminum metal and GFRP layer of FML composites. The surfaces of the aluminum interface layer are engraved with three kinds of patterns by using the laser machine before the hot press works. Furthermore, the effect of the laser patterns on the interfacial toughness is investigated. The interfacial toughness was evaluated by the energy release rate (G) using an asymmetric double cantilever bending specimen (ADCB). From the experimental results, it was shown that the strip type pattern (STP) has the most proper pattern shape in GFRP/Al FML composites. Therefore, this will be considered a useful method for the safety assessment of FML composite structures.

• Journal of the Korean Society of Safety
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• v.27 no.2
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• pp.78-83
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• 2012

This is a study to confirm how to improve and substitute the existing re-bar with other material such as a fiber rope, especially super fiber rope having much more strong tensile strength. 6(b) different fiber rope reinforced beam with a section of $20{\times}30cm$ have been made and tasted as variables designed in the study. The larger diameter of fiber rope, the more capacity of the beam, even though fiber reinforced beam are increased with ten(10)percent, each. Lower capacity of fiber-reinforced beam than normal RC beam has been analyzed theoretically and empirically, based on a lot of experiences of the same size beam test. Fiber rope-reinforced concrete beam does not have sufficient capacity than RC beam due to insufficient bonding capacity of fiber rope in concrete. It leads to decrease beam bearing capacity and crack around lower center of the beam. Therefore, bonding reinforcement of fiber rope beam such as pinning a triangles steel pin in each knot of fiber rope contributes to improving bearing capacity of fiber rope reinforcing beam.

• Journal of Korea Technical Association of The Pulp and Paper Industry
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• v.38 no.4 s.117
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• pp.17-23
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• 2006

Paper has fibers and fines network structure and it is strongly affected by interface bond-ing between fibers. Paper structural properties can be determined depending on the inter-fiber bonding. Fines play an important role in Campbell and consolidation effect through wet pressing and drying operations. The fines are essential for the formation of bonds between fibers and for the improvement of strength properties of papers. Since the fines are components of the pulp, there are always two factors to be considered: the quality and quantity of the fines. The quality of fines might be a potential variable to give a more accurate picture of the papermaking potential of the pulp. The object of this study is to investigate the effect of different types of pulp fines on the properties of paper and to access the potential of fines for controlling the bulk of paper. Refined Sw-BKP, Hw-BKP and BCTMP fines were used to investigate the fines effect. Wet-web strength, breaking length, scattering coefficient, and hydrodynamic specific volume, and drying shrinkage were measured. According to the results, chemical and morphological compositions of fines do not strongly affect to wet-web forming by their similar Campbell effect, but strongly affect to drying operation which forms hydrogen bonding among fiber-fines-fiber matrixes. Paper bulk should be controlled by the extent of hydrogen bonding between fibers during drying operation.

• Proceedings of the Korean Fiber Society Conference
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• 1997.04a
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• pp.6-10
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• 1997

• Textile Coloration and Finishing
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• v.20 no.4
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• pp.21-30
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• 2008

To understand the complex hydrogen bonding structure, several phenolic derivatives and benzoxazine model compounds are synthesized and characterized by Fourier transform infrared spectroscopy (FT-IR). The estimation of molar extinction coefficients for various types of hydrogen bonding species is systematically carried out by the curve-resolving of FT-IR spectra. The distribution of hydrogen bonding species in benzoxazine model dimers is quantitatively analyzed. It is revealed that benzoxazine dimers and BA-a polybenzoxazine are mainly composed of intramolecular interaction rather than intermolecular interaction.

• Journal of the Korean Society for Nondestructive Testing
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• v.30 no.3
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• pp.236-243
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• 2010

Fiber Bragg grating(FBG) sensor arrays can be used to monitor the mechanical behavior of the large composite structures such as wind turbine rotor blades and aircrafts. However, brittle FBG sensors, especially multiplexed FBG sensors are easily damaged when they are installed in the flexible structures. As a protection of brittle FBG sensors, epoxy packaged FBG sensors have been presented in this paper. Finite element analysis and experiments were performed to evaluate the effects of adhesives, packaging materials and the bonding layer thickness on the strain transmission. Two types of epoxy were used for packaging FBG sensors and the sensor probes were attached with various bonding layer thickness. It was observed that thin bonding layer with high elastic modulus ratio of the adhesive to packaging provided good strain transmission. However, the strain transmission was significantly decreased when elastic modulus of the adhesive was much lower than the packaged FBG sensor probe's one.

• Proceedings of the Korean Geotechical Society Conference
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• 2008.03a
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• pp.267-272
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• 2008

The purpose of this study is to improve the environmental applicability of nonwovens by using special composition. Polypropylene spunbonded and needle punched nonwovens which have the lower cost than polyester nonwovens were used as the raw materials to manufacture the natural fiber used nonwoven geotextiles. These geotextiles were made by use of the thermal bonding methods and composed of jute(or flax)/polypropylene staple fiber blends were obtained in consideration of environmental application. Finally, the engineering properties of natural fiber used nonwoven geotextiles were investigated as eco-friendly materials.

• Proceedings of the Korea Concrete Institute Conference
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• 2000.10a
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• pp.785-792
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• 2000

Repair and retrofit system of concrete structures has been developed from conventional reinforced concrete overlaying, steel plate bonding and recently to fiber composite systems. Research and study on carbon, aramid, and glass fiber composite system has been actively carried out from all over the world Glass fiber composite is proved to be competitive technically and enconomically, among fiber composite system. CAF system is a system developed locally using all domestic materal, glass fabric and epoxy, and improved in shear bonding property by utilizing silica fume mixed with epoxy. All the tests on material properties, structural behavior, constructiveness at site and quality control procedure proved to be most appropriate system so far developed. Futher research work is and will be under progress for utilization of this system which will be applied to more adverse situation.

• Proceedings of the Korea Concrete Institute Conference
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• 1998.10b
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• pp.815-820
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• 1998

Many composite girder bridges have been constructed for about thirty five years. Nowadays they are aged or deteriorated because of th increase in traffic and vehicle loads. In this study, the effect of strengthening with glass fiber sheet is investigated to estimate the possibility for appling for damaged prestressed concrete bridges. One normal and eight cracked specimens which had been preloaded were tested. The cracked specimens were strengthened with either external prestressing or bonding glass fiber sheet, or using both methods. The results showed that the maximum loads are almost same for both methods. So it seems that the strengthening with glass fiber sheet can be used for strengthening damaged prestressed concrete girders. It is important that proper devices should be selected to prevent glass fiber sheet from premature bonding failure below its maximum load, which is similar to end anchorage problem in external prestressing method. It is proved that the devices proposed in this paper have sufficient anchoring capability to increase load carrying capacity.