• 한국공작기계학회:학술대회논문집
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• 한국공작기계학회 2002년도 춘계학술대회 논문집
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• pp.64-69
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• 2002

The purpose of this paper was to investigate the welding characteristics and the fatigue crack propagation behavior of titanium commonly using power station, aircraft and ship. The experimented material was TIG welded in order to look over the characteristics according to the notch position and compare with other materials. We compared and reviewed the fatigue crack propagation behavior of nontch base metal and welded specimens having different notch position to evaluate the fatigue crack propagation behavior by welding condition.

• 한국경영과학회:학술대회논문집
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• 대한산업공학회/한국경영과학회 1995년도 춘계공동학술대회논문집; 전남대학교; 28-29 Apr. 1995
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• pp.758-759
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• 1995

In large-scale industry such as shipbuilding, aircraft manufacturing, and construction industry etc., it is required to consider two or three-dimensional spatial availability as one of bottlenecked resource constraints. We call this kind of scheduling a spatial scheduling, which considers the dynamic spatial layouts of objects as well as the traditional resource constraints. Since 1991, we have researched on the spatial scheduling for shipbuilding plant (Lee & Lee, 1992; Lee et al., 1994, Lee et al., 1995). In this paper, we present the various issues of spatial scheduling for the researchers and developers attacking spatial scheduling problems.

• 한국생산제조학회지
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• 제7권1호
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• pp.58-68
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• 1998

Advantages of adhesively bonded joints and techniques of weight reduction have led to increasing use of structural adhesives such as LSI(large scale integration) package, automobile, aircraft in the various industries. In spite of such wide applications of adhesively bonded joints, the evaluation method of bonding strength has not been established. Stress singularity occurs at the interface edges of adhesively bonded joints and it is required to analyze it. In this paper, the stress singularity using 2-dimensional elastic boundary element method (BEM) with the changes of the lap length and adhesive for single lap joint was analyzed, and experiments of strength evaluation were carried out. As the results, the evaluating method of bonding strength considering stress singularity at interface edges of adhesively bonded joints and stress intensity factor of interface crack have been proposed in static and fatigue test.

• 한국기계가공학회지
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• 제19권6호
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• pp.23-28
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• 2020

A non-linear vibration isolation system composed of a non-linear spring and a linear damper was presented in a previous study. The advantage of the proposed isolator is the simple structure of the system. When the base of the isolator is harmonically excited, the response component of the mass at the excitation frequency was approximated using three different methods: linear approximation, harmonic balance, and higher-order frequency response functions (FRFs). The method using higher-order FRFs produces significantly more accurate results compared with the other methods. The error between the exact and approximate responses does not increase monotonously with the excitation amplitude and is less than 2%.

• Management Science and Financial Engineering
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• 제10권2호
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• pp.73-87
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• 2004

Automotive and aircraft assembly process rely on fixtures to support and coordinate parts and subassemblies. Fixture layout in multi-station panel assemblies has a direct dimensional effect on final products and thus presents a quality problem. This paper describes a methodology for fixture layout design in multi -station assembly processes. An optimal fixture layout improves the robustness of a fixture system against environmental noises, reduces product variability, and eventually leads to manufacturing cost reduction. One of the difficulties raised by multi-station fixture layout design is the overwhelmingly large number of design alternatives. This makes it difficult to find a global optimality and, if an inefficient algorithm is used, may require prohibitive computing time. In this paper, simulated annealing is adopted and appropriate parameters are selected to find good fixture layouts. A four-station assembly process for a sport utility vehicle (SUV) side frame is used throughout the paper to illustrate the efficiency and effectiveness of this methodology.

• 통상정보연구
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• 제11권2호
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• pp.303-328
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• 2009

MERCOSUR, which is the biggest economic community in the Latin America, has great potential as Korea's export market with 220 million population and 2.8 trillion$ GDP. In the midst of global economic crises, the importance of MERCOSUR is highlighted with relatively sound economic growth. The average tariff rate of MERCOSUR is 10.4~12.2% which is almost same as that of Korea(12.2%), but the tariff rates on Korea's main export items such as auto, display, digital camera, mobile phone are as high as 20~30%, which means that Korea-MERCOSUR FTA will result in substantial growth of Korea's export. In pursuing Korea-MERCOSUR FTA, cooperations in natural resources, agriculture, mid-sized aircraft, construction and green energy as well as liberalization of commodity market are very important for Korea. To realize Korea-MERCOSUR FTA, it is essential to overcome the objections from the manufacturing sectors of MERCOSUR. So it is desirable to aim relatively low in terms of the level of liberalization at the beginning, and expand corporate and industrial cooperation between Korea and MERCOSUR's manufacturing industries.

• 한국복합재료학회:학술대회논문집
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• 한국복합재료학회 2002년도 추계학술발표대회 논문집
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• pp.183-188
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• 2002

Co-cured composite materials has its own characteristics, so its thermal expansion is different each other. The selection of tool material for co-cured composite part in high temperature more over $350^{circ}F$ and 50 Psi pressure have to consider part thermal expansion, size, shape, and economic aspect in production line. So it is important choose tooling material in manufacturing composite parts. We called the tool for airplane composite parts as BAJ (Bonding Assembly Jig). Composite parts are cured on the BAJ in autoclave. BAJ have to stable at high temperature over $350^{circ}F$ and 50 Psi pressure, Considering composite parts' dimensional tolerance compare to heat up in autoclave. This paper come from the results of the experiment at the composite parts production line and review other aircraft company's method for tooling This is for the engineer engaged in composite parts manufacturing.

• 한국복합재료학회:학술대회논문집
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• 한국복합재료학회 2002년도 추계학술발표대회 논문집
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• pp.193-197
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• 2002

Polyurethane casting wing fairings included in F-5E/F 15% spar kit are to be installed on aircraft wing surfaces and used for compensating the changes of the aerodynamic configuration by the leading edge extension fairings. These fairing are mandatory items in repairing wing areas and was imported from foreign supplier with long term delivery and high cost. Accordingly, local manufacturing is necessary to get rid of above disadvantages such as long term delivery and high cost. Basic properties test of specimen to be developed and part's requirements after localization was taken and its values were similar or higher when comparing with the original's even in low temp test at -55C. Casting mold process was used to manufacture the polyurethane fairings and its demensional stability ＆ physical condition was proper and met to the related specification and drawing's requirements

• 한국기계가공학회지
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• 제11권3호
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• pp.110-115
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• 2012

For domestic aircraft industry, not mass production of components is limited, small production scale of the order is made by part because many kinds of hundreds of thousands of kinds of small quantity batch production system are taking. But the high reliability and stability are required during the processing because they require high precision parts are required. It is found that when C-axis rotation speed was increased, the diameter of the cutting tool decreased with increasing surface roughness, while the turn-mail feed rate was increased with increasing the surface roughness.

• 한국생산제조학회지
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• 제22권2호
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• pp.337-341
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• 2013

In this study, fatigue crack propagation in composite material under fatigue is investigated by simulation result. When another material on the specimen exists vertically to the crack line, the phenomena that crack may go straight or propagate along the boundary face according to the elastic modulus ratio of another material to matrix are investigated with compact tension specimen by compliance method. Crack propagation direction is evaluated by compliance method. By arranging this study result systematically about the crack propagation behavior due to the stiffness of inhomogeneous material, high-tech material (automobile, aircraft and steel industry) can be improved. The estimation of safety design and life (construction & nuclear power station, etc.) will be of great value industrially.