• Journal of the Korean Society of Manufacturing Process Engineers
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• v.20 no.6
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• pp.51-58
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• 2021

The notion of leisure has changed with industrial development and improvement in life quality. Bicycling is a healthy sport; it is an exercise performed while enjoying nature. There have been many changes in the materials that are used to manufacture the bicycle frame. Iron and aluminum have been mainly used in bicycle frames. However, carbon-based materials are lighter and stronger than metal frames. The bicycles made of carbon composite changes frame rigidity depending on the direction of the carbon sheet sacking angle. We study the direction of composite material and how they affect the stiffness of frames based on the stacking angle.

• Journal of the Korean Society for Precision Engineering
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• v.34 no.2
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• pp.139-143
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• 2017

Finite element analysis was performed for a split-type CFRP bicycle frame, which was designed to apply a compression molding process with carbon fiber prepreg for a conventional bicycle. An epoxy adhesive material for joining the frames was selected by the extent of stress at joint interfaces. The split-type bicycle frame was then formed and its weak parts examined by the boundary conditions according to reliability tests. The results verified the reliability of the bicycle frame after modification of these weak parts. The finished product was manufactured by using this developed split-type bicycle frame.

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.27 no.4
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• pp.178-185
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• 2017

Carbon fiber frames are actively developed for developing carbon fiber frames as the material of the next generation of bicycle frames, and are currently being developed with carbon fiber frames, hardness, shock absorption, light intensity, and strength. The carbon fiber bike models require a premium, differentiated design concept, which is essential to the development of a conceptual and differentiated design, requiring the development of essential structural structures, safety and refinement, and more of their own identity. In this study, a personal and unified image was derived from the research of the needs of consumers and image analysis process and then in the practical design work, the road bike bicycle frame design was proposed targeting the frame on the basis of carbon fiber materials.

• Journal of Ocean Engineering and Technology
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• v.27 no.6
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• pp.65-72
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• 2013

This paper describes a finite element analysis (FEA) of the body frame of a subsea robot, Crabster200 (CR200). CR200 has six legs for mobility instead of screw type propellers, which distinguishes it from previous underwater robots such as remotely operated vehicles (ROVs) and autonomous underwater vehicles (AUVs). Another distinguishing characteristic is the body frame, which is made of carbon fiber reinforced plastic (CFRP). This body frame is designed as a rib cage structure in order to disperse the applied external loads and reduce the weight. The frame should be strong enough to support many devices for exploration and operation underwater. For a reasonable FEA, we carried out specimen tests. Using the obtained material properties, we performed a modal analysis and FEA for CR200 with a ready posture. Finally, this paper presents the FEA results for the CFRP body frame and the compares the characteristics of CFRP with conventional material, aluminum.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2011.05a
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• pp.193-195
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• 2011

Nowadays, climatic environment change has become a major issue in the world. This causes major emissions of carbon dioxide industries steel industry, thermal power industry, cement industry is essential in the reduction of carbon dioxide, which is based on total carbon dioxide emissions account for most of the construction industry in an effort to minimize the environmental load is needed. accordingly, through case studies, It can be induce the selection to minimize environmental load by comparing the output of quantitative energy consumption and carbon dioxide emissions per constructional methods. As a result of this study, RC Structure was less environmental load than SC structure.

• Transactions of the Korean Society of Automotive Engineers
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• v.25 no.3
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• pp.350-359
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• 2017

This paper presents a new holistic development approach for the carbon continuous-fiber composite frame of an automotive sunroof assembly. The original steel frame has been designed to get higher bending stiffness with its corrugated cross-sectional shape. The new approach uses the prepregs of a fast cure epoxy and PCM manufacturing processing. For higher productivity, the new frames feature a very simple plat cross sectional shape but achieve high bending stiffness through the laminate design. The sandwich structure with a PET foam core was presented. The frames were made of carbon UD laminae covered single carbon fabric on the outer surfaces. The fabrics provide torsional stiffness and also hold the carbon UD fibers floating in the low viscous epoxy resin of prepregs at the curing temperature during processing. The final product yields approximately 18 % savings in weight compared with the original.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.18 no.1
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• pp.46-51
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• 2019

As the industry develops and quality of life increases, the concept of leisure is also changing. Bicycling is a healthy sport for exercising while enjoying nature, facilitating the enjoyment of a healthy life. As a result, the awareness surrounding bicycles has increased, and so has the interest in lighter and more luxurious carbon bikes. The number of domestic companies producing carbon bicycles frames is nil. In this study, we analyze the frames of existing foreign brands and analyze the deformation and stress concentration area according to the load of the frame, using the finite element analysis. In addition, we set up the range of stiffness based on the content of the structural analysis, to localize the carbon bicycle frame and famous foreign products, and compare the prototype with the stiffness by using bicycle molds for track races.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.17 no.3
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• pp.127-133
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• 2018

To reduce fuel consumption, research on the weight reduction of vehicles is being actively carried out. Researchers have typically tried to replace metal materials with composites materials, but these materials did not satisfy the required strength and rigidity of a vehicle. Composites are usually not used because of their high cost. There are incomplete studies on lightweight trucks that transport cargo. Therefore, in this paper, we enhance the lightness and mechanical strength through design optimization of the deck frame for a lightweight truck. For that purpose, the side member and cross member, which are mounted on the lower part of the truck to assure the safety of the vehicle and support the luggage load, were targeted. The result of numerical analysis on the safety of the frame was obtained by changing the shape of each cross-section. To verify the numerical analysis, we compared it with the theoretical value of a cantilever beam. As a result, the suitability of the cross-sectional shapes of each frame was confirmed through numerical analysis.

• Proceedings of the Korean Society For Composite Materials Conference
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• 2004.10a
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• pp.232-235
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• 2004

This is the preliminary study to develop composite window frame of commercial aircraft using VaRTM process. For two candidate carbon fabric(triaxial fabric, sleeving braider dry carbon fiber), specimens were fabricated using VaRTM process ,and then the physical & mechanical tests were performed to gain material property according to ASTM. FEM analysis for each candidate carbon fabric were performed to find the minimum ply number and weight for composite window frame. In this study Tsai-Wu strength failure criteria was utilized to evaluate the safety of structure.

• Earthquakes and Structures
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• v.23 no.5
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• pp.473-491
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• 2022

The research investigates experimentally the effect of confinement on structural behavior at the ends of beam-column in reinforced concrete (RC) frames. In the experimental study, five specimens consisting of 1/3-scaled RC frames having single-bay, representing the traditional deficiencies of existing buildings constructed without receiving proper engineering service is investigated. The RC frame specimens were produced to represent most of the existing buildings in Turkey that have damage potential. To decrease the probable damage to the existing buildings exposed to earthquakes, the carbon Textile Reinforced Mortar (TRM) strengthening technique (fully wrapping) was used on the ends of the RC frame elements to increase the energy dissipation and deformation capacity. The specimens were tested under reversed cyclic lateral loading with constant axial loads. They were constructed satisfying the weak column-strong beam condition and consisting of low-strength concrete, such as compressive strength of 15 MPa. The test results were compared and evaluated considering stiffness, strength, energy dissipation capacity, structural damping, ductility, and damage propagation in detail. Comprehensive investigations of these experimental results reveal that the strengthening of a brittle frame with fully-TRM wrapping with non-anchored was effective in increasing the stiffness, ductility, and energy dissipation capacities of RC bare frames. It was also observed that the frame-only-retrofitting with an infill wall is not enough to increase the ductility capacity. In this case, both the frame and infill wall must be retrofitted with TRM composite to increase the stiffness, lateral load carrying, ductility and energy dissipation capacities of RC frames. The presented strengthening method can be an alternative strengthening technique to enhance the seismic performance of existing or moderately damaged RC buildings.