• Proceedings of the Korea Concrete Institute Conference
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• 2010.05a
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• pp.121-122
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• 2010

In this research, reinforced concrete beam-column joint is examined. The main purpose of the research is assessment of influence the beam longitudinal reinforcement slippage to the joint shear and ductile capacity caused by bond decrement as a result of plastic hinges in adjacent beam.

• Proceedings of the Korea Concrete Institute Conference
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• 2010.05a
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• pp.25-26
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• 2010

Strain-hardening cementitious composite(SHCC) has been expected excellent reinforcement performance in beam-column joint area. The main variables considered include the type of cement composites(premixed mortar, SHCC with hybrid fiber) and shape and existence of the tie bar. As the result of the tests, existence of the tie bar specimen showed better overall behavior than another.

• Proceedings of the Korea Concrete Institute Conference
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• 2010.05a
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• pp.97-98
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• 2010

This paper discusses shear behavior of Joint with premix mortar and strain hardening cement composites(SHCC) with PVA and PE fibers. The main variables considered include the type of cement composites(premixed mortar, SHCC with hybrid fiber) and reinforcement. It was evaluated that shear load had a good accordance with the test and equation result.

• International Journal of Ocean Engineering and Technology Speciallssue:Selected Papers
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• v.4 no.1
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• pp.38-43
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• 2001

This paper provides review of research results undertaken on reinforced concrete wall panels in one way and two way. The review also highlights two well accepted code design methods from the American (ACI) and Australia Concrete structures standards. The emphasis is on walls under axial compression only with changes in various parameters. These include the variation of panel dimensions panels (ie. Slenderness, thinness and aspect ratios), steel reinforcement, eccentricities, concrete strength and support conditions. The main purpose of this review is to compile research previous by undertaken to highlight the inadequate in certain research literature. It is envisage that this review will expose areas in wall research required so that inadequate in current methods can be rectified.

• Journal of Korea Foundry Society
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• v.13 no.3
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• pp.285-294
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• 1993

Aluminum alloy 2024 matrix composites reinforced with $Al_2O_3$ particles, were prepared by rheo-compocasting, a process which consists of the incoporation distribution of reinforcement by stirring within a semi-solid alloy. The microstructures and characteristics of the interfaces have been studied using optical microscope and scanning electon microscope in 2024 aluminum alloy composites reinforced with $Al_2O_3$ particles. The main results are as follows: (1) $Al_2O_3$ particles were well distributed in composites by using rheo-compocasting. (2) As the addition of $Al_2O_3$ particle increases, the average dendrite numbers and the hardness were increased. (3) Interaction between $Al_2O_3$ particles and alloy 2024 resulted in the formation of Mg and Cu element rich region around the $Al_2O_3$ particles.

• Journal of the Korean Society for Precision Engineering
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• v.30 no.9
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• pp.983-990
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• 2013

Evaluation of the structural analysis for a 70/15 ton${\times}$105 m LLC (Level Luffing Crane) was conducted with an FEM Tool. Due to a discordance of the modeling and element type, the LLC was progressively analyzed after dividing it into the boom, main structure and rocker. All loads such as slewing, traveling and wind load, etc., that are indicated in the reference standards, were inputted as various severe conditions of the LLC. The deformation, equivalent stress(Von Mises stress), buckling characteristics were evaluated for the LLC structures. The stress concentrated areas over the allowable stress were identified, and reinforcement work was performed with a stiffener.

• Journal of Power System Engineering
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• v.12 no.6
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• pp.83-87
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• 2008

EPS(Electric Power Steering) system, which has replaced the hydraulic steering system(HPS or HPAS) in many passenger cars recently, have many merits such as low energy consumption, easy mounting, light weight and improvement of environmental pollution. However, EPS system has the problem of motor noise when motor is rotated, which can make a driver feel uncomfortable. There are many techniques to solve those problems, but they are not clear. It is necessary to evaluate the mechanical noise in steering systems, because an EPS has vibration sources such as at the motor gear reducer, manual gears and intermediate joints. In this paper, reduction technique of EPS motor noise is introduced.

• Proceedings of the KWS Conference
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• 2006.05a
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• pp.304-306
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• 2006

Positioning the workpiece accurately and preventing the weld distortion, tack welding is often performed before main welding in the construction of welded structures. The weld bead size of the tack weld is determined according to the workpiece thickness, weld length, weld joint type etc. However, this tack weld deteriorates the final weld bead profile, so that the grinding process is usually adopted for the uniform weld bead profile. In this study, an experimental method for the selection of optimal welding condition was proposed in the fillet weld which was done over the tack weld. This method uses the response surface analysis in which the leg length and the reinforcement height of weld bead were chosen as the quality variables of weld bead profile. The overall desirability function, which was combined desirability function for the two quality variables, was used as the objective function for getting the optimal welding condition. From the result, it was revealed that a uniform weld bead can be obtained by adopting the optimal welding condition which was determined according to the method proposed.

• Proceedings of the Korea Concrete Institute Conference
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• 2003.05a
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• pp.255-260
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• 2003

The corrosion of steel rebars has been the major cause of the reinforced concrete deterioration. It is FRP rebar that is developed to solve problem of such steel rebar. FRP rebar in concrete structures should be used as a substitute of steel rebars for that cases in which aggressive environment produce high steel corrosion, or lightweight is an important design factor, or transportation cost increase significantly with the weight of the materials. But FRP rebar have only linearly elastic behavior; whereas, steel rebar has linear elastic behavior up to the yield point followed by large plastic deformation and strain hardening. Thus, the current FRP rebars are not suitable concrete reinforcement where a large amount of plastic deformation prior to collapse in required. The main objective of this study was to develop new type of hybrid FRP rebar. The manufacture of the hybrid FRP rebar was achieved pultrusion, braiding and filament winding techniques. Tensile and interlaminar shear test results of hybrid FRP rebar can provide its excellent tensile strength-strain behavior and interlaminar stress-strain behavior.

• Journal of the Korean Society of Safety
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• v.21 no.6 s.78
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• pp.96-100
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• 2006

In this thesis, the crack investigation, the damage investigation, the drawing check, and the structural analysis were performed on a curved hollow RC(reinforced concrete) slab bridge structure to assess the structural safety of that. From the crack investigation result, main reason of crack occurrence is guessed with travelling of the large truck. Therefore reinforcement of slab structure is necessary by using the steel plate. When structural analysis, the straight beam model, the curved beam model, and the curved plate model is used. From the results of structural analysis for curved hollow RC slab bridge, the maximum bending moment and the maximum shear force was not a difference in each models. But the vertical displacement of mid span using the curved beam model was greater than that using the other models.