• Special Issue of the Society of Naval Architects of Korea
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• 2011.09a
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• pp.95-100
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• 2011

In general, thickness of bottom floor in fore/aft cargo hold region for container ship has been determined based on FEM analysis result of mid cargo hold region. But this approach has room for improvement because section shape and frame spacing in fore/aft cargo hold of container ship are quietly different from those of mid cargo hold. From this study, correlation between FEM result and grillage analysis result has been investigated and simple method for thickness determination of bottom floor in fore/aft cargo hold using newly improved grillage analysis is proposed.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• v.1
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• pp.321-325
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• 2006

Because strong wind is one of the few forces that, although considered in container crane design, still cause significant damage, a container crane was tested to investigate wind load characteristic in uniform flows. So, this study measured an external point pressure at the each members of a container crane according to a wind direction and a shape of members in a wind-tunnel test. The result of this test was compared to those of computation fluid dynamics using a CFX 10. The scale of a container crane model for wind tunnel test applied similarity scales to consider the size of the wind tunnel test section and the boundary condition for CFD is like wind tunnel test.

• Conservation Science in Museum
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• v.25
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• pp.1-8
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• 2021

This study investigated White Porcelain Water Dropper with Openwork Lotus Scroll Design and Eight Trigram Design in Cobalt-blue Underglaze (hereinafter, the "water dropper") in the collection of the National Museum of Korea using computed tomography (CT). A replica was produced to examine both the structure and its original production method. The CT scanning identified no joint lines or pores in the clay, which suggests that the body (the lower part of the water dropper) was shaped in a single piece using a mold and was then matched with a mold-formed lid (the upper part of the water dropper). The inner container of the body portion was roughly trimmed with a bamboo knife so that its upper surface could be securely attached to the bottom of the lid and prevent any leakage in the joined surface. It appears that the inner container for storing water was made first in a cylindrical shape that met the unit of quantity used at the time and could be easily formed by molding. It was transformed into a trapezoid shape during the process of combining it with the lid. A cylindrical inner container was reproduced using silicon 3D printing to compare its capacity with that of the original inner container. The comparison revealed that the reproduced container had a capacity of 152.5㎖, whereas the original container holds approximately 168.6㎖, a figure similar to three hop (around 174㎖) in Joseon-period units of quantity. Since the capacity of the cylindrical inner container corresponds to a known measure from the late Joseon dynasty, it is likely that the water dropper was originally produced to contain a cylindrical inner container.

• Journal of Radiation Industry
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• v.17 no.2
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• pp.191-197
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• 2023

Abstract KOMAC(Korea Multi-Purpose Accelerator Complex, KAERI) has been operating a 100 MeV proton accelerator and is going to produce ⁶⁸Ga isotope which is useful for diagnosis of cancer. So, it is necessary to develop a transport container for radio-activated targets. In this study, we carry out shielding analysis and structural analysis for the radio-activated target transport container using simulation programs. According to the Type A standard, the transport container includes an inner container and an overpack container. The main material of inner container is lead, and the shape is cylindrical with diameter of 152mm, height of 142mm and weight about 29 kg. It is planned to verify the possibility of field application through production of the transport container prototype in the future.

• Journal of Navigation and Port Research
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• v.33 no.3
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• pp.215-220
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• 2009

Container cranes are vulnerable structure to difficult weather conditions bemuse there is no shielding facility to protect them from strong wind. This study was carried out to analyze the effect of wind load on the structure of a container crane according to the change of the boom shape using wind tunnel test and computation fluid dynamics. And we provide a container crane designer with data which am be used in a wind resistance design of a container crane assuming that a wind load 75m/s wind velocity is applied in a container crane. In this study, we applied mean wind load conformed to 'Design Criteria of Wind Load' in 'Load Criteria of Building Structures' and an external fluid field was divided as interval of 10 degrees to analyze the effect according to a wind direction. In this conditions, we carried out the wind tunnel test and the computation fluid dynamic analysis and than we analyzed the wind load which was needed to design the container crane.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2006.06b
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• pp.311-316
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• 2006

This study was carried out to analyze the effect of wind load on the structural stability of a container crane according to the change of the boom shape using wind tunnel test and provided a container crane designer with data which can be used in a wind resistance design of a container crane assuming that a wind load at 75m/s wind velocity is applied on a container crane. Data acquisition conditions for this experiment were established in accordance with the similarity. The scale of a container crane dimension, wind velocity and time were chosen as 1/200, 1/13.3 and 1/15. And this experiment was implemented in an Eiffel type atmospheric boundary-layer wind tunnel with $11.25m^2$ cross-section area. Each directional drag and overturning moment coefficients were investigated and uplift forces at each supporting point due to the wind load were analyzed.

• Transactions of Materials Processing
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• v.3 no.3
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• pp.359-374
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• 1994

Process sequence design in sheet metal forming process by the finite element method is investigated. The forming of sheet metal into a washing machine container is used to demonstrate the design of an improved process sequence which has fewer operations. The design procedure makes extensive use of the finite element method which has simulation capabilities of elastic-plastic modeling. A one-stage process to make an initial blank to the final product is simulated to obtain information on metal flow requirements. Loading simulation for a conventional method is also performed to evaluate the design criteria which are uniform thickness distribution around the finished part and maximum punch load within limit of available press capacity. The newly designed sequence has two forming operations and can achieve net-shape manufacturing, while the conventional process sequence has three forming operations. This specific case conventional process sequence has three forming operations. This specific case can be considered for application of the method and for development of the sequence design methodology in general.

• International Journal of Naval Architecture and Ocean Engineering
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• v.6 no.2
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• pp.187-205
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• 2014

The global price of oil, which is both finite and limited in quantity, has been rising steadily because of the increasing requirements for energy in both developing and developed countries. Furthermore, regulations have been strengthened across all industries to address global warming. Many studies of hull resistance, propulsion and operation of ships have been performed to reduce fuel consumption and emissions. This study examined the design parameters of the propeller boss cap fin (PBCF) and hub cap for 6,000TEU container ships to improve the propulsion efficiency. The design parameters of PBCF have been selected based on the geometrical shape. Computational fluid dynamics (CFD) analysis with a propeller open water (POW) test was performed to check the validity of CFD analysis. The design of experiment (DOE) case was selected as a full factorial design, and the experiment was analyzed by POW and CFD analysis. Analysis of variance (ANOVA) was performed to determine the correlation among design parameters. Four design alternatives of PBCF were selected from the DOE. The shape of a propeller hub cap was selected as a divergent shape, and the divergent angle was determined by the DOE. Four design alternatives of PBCF were attached to the divergent hub cap, and the POW was estimated by CFD. As a result, the divergent hub cap with PBCF has a negative effect on the POW, which is induced by an increase in torque coefficient. A POW test and cavitation test were performed with a divergent hub cap with PBCF to verify the CFD result. The POW test result showed that the open water efficiency was increased approximately 2% with a divergent hub cap compared to a normal cap. The POW test result was similar to the CFD result, and the divergent hub cap with the PBCF models showed lower open water efficiency. This was attributed to an increase in the torque coefficient just like the CFD results. A cavitation test was performed using the 2 models selected. The test result showed that the hub vortex is increased downstream of the propeller.

• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 1994.10a
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• pp.107-117
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• 1994

A design methodology is applied for manufacturing a disk-brake piston component and a washing machine container. The design criteria are the limit drawing ratio and the forging load within the available press limit. Also, the final product should not have any geometrical defect. The rigid-plastic and elastic-plastic FEM have been applied to simulate both of the conventional manufacturing processes, respectively, which include deep drawing and forging process. Simulations of one stage process from a selected stock to the final product shape are performed for generating information on additional requirements for metal flow. The best manufacturing processes are selected, which is using a hemispherical punch in the deep drawing process for both disk-brake piston component and washing machine container.

• Transactions of Materials Processing
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• v.25 no.4
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• pp.227-234
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• 2016

In the transportation between countries using container, too many empty containers must be transported due to the transportation unbalance. For transportation efficiency, therefore, foldable containers are being developed. Hinge brackets are important parts of foldable containers because great force is applied on the hinges during loading onto and unloading from ships. In this study, the hinge bracket for a foldable container is designed to be made using thick plate or bulk materials to endure the heavy loads. The forming process for the hinge bracket using a thick plate is designed via numerical analysis. First of all, the shape of bracket is designed for the better formability. Bending and successive side wall thickening processes are employed for the forming of the hinge bracket. Maximum thickening that can be achieved in a single stage of forming without a folding defect is determined and three stage of thickening processes are designed.