• Journal of Ocean Engineering and Technology
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• v.15 no.1
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• pp.85-91
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• 2001

A study for the structural strength analysis on the doubler plate subjected biaxial in-plane compression and shear load has been performed through the systematic evaluation process. In order to estimate the proper static strength of the doubler plate, non-linear elasto-plastic analysis is introduced. Gap element modeling for contact effect between the main plate and the doubler is prepared and nonlinear analysis procedures are illustrated based on MSC/N4W. In addition, some design guides are suggested through the consideration of several important effects such as corrosion of main plate, doubler width, doubler length and doubler thickness. Finally, theses result are compared with a developed design formula based on the buckling strength and general trends. The design guides, according to the variation of design parameters are discussed.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.22 no.5
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• pp.87-92
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• 2022

In this paper, a study was conducted on the design of an array element that can be applied to the AESA radar for seeker. An antenna for application to AESA radar should choose an optimal radiation element to be applied to an array antenna in order to secure electronical beam steering characteristics, and consider beam steering characteristics when designing. In particular, in order to satisfy the wide-angle beam steering characteristics, the wide-angle impedance matching technique should be used to minimize the scan blindness region that may occur during wide-angle steering. As such, securing the stability of system operation is becoming an important design consideration for AESA radar. In this paper, WAIM is applied to the end of the radiation element to improve the characteristics of the radiation element applied to the AESA radar antenna device, and the change in the performance of the active reflection coefficient, which is a stable operation index of the system, is reviewed. The final performance result verified the validity of the proposed method by mathematically synthesizing the simulation data.

• Journal of the Korean Institute of Landscape Architecture
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• v.30 no.1
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• pp.44-51
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• 2002

The objective of this project is to improve the environment of the estuary dike on the Youngsan-River through Re-landscaping. An estuary dike of the Youngsan-River, the largest in the Orient, was constructed in 1981 and connects Mokpo City and Youngam-Gun province. Twenty years ago, when this dike was completed, this place was one of the famous tourist attractions of Korea. It symbolized the development and growth of Korea. But this dike at present is only a dreary sight as a huge concrete construction element. Therefore, a wall painting on the estuary dike was planned to improve this image. The site, an estuary dike of the Youngsan-River, is located in Mokpo City and its length is about 1,360m. The planning focus of this re-landscaping, which is a proposed improvement design through the analysis of characteristics and problems in conventional facilities, is as follows: (1) Introduction of a wall painting that is a symbol of the sea and river (by the creation of an illusion), (2) Production of the wall painting which is under consideration to create a friendly atmosphere of the circumference view and (3) Preparation of a design to establish an approach to the waterfront. By following these steps, an estuary dike can function as a tourist attractions and can be transformed in to cultural space for civilian. This project is good example of environment design that is completed with the regional residents participation through community input in the planning and initiation of a wall painting. The concept of environment design which involves the residents participation and re-landscaping in Korea has not been established up to now on. However, as this projects has proven, consideration for regional residents is a very important factor for the administrative office and planing specialist to address. In the future, it will have a direct influence on the development of design planning. If the establishment of space that can be accepted by residents with love, affection and self-confidence is possible, environment design in which residents participate actively, can be realized.

• The Transactions of the Korean Institute of Electrical Engineers B
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• v.51 no.7
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• pp.364-369
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• 2002

In this paper, 3-D magnetostatic finite element simulation of a rotux type Low-Tc superconducing (LTS) superconducting power supply, finite element method, cryogenic system, superconducting foil by generated magnetic flux from the rotating pole. The magnetic flux density on the superconducting foil caused by two exciters is therefore sufficiently greater than its critical magnetic flux density and it is an essential point in LTS power supply design. To establish the sufficient flux path of this machine, ferromagnetic materials is used in this power supply. When ferromagnetic materials is used at extremely low temperature, its characteristic of magnetization differs to that at room temperature. For this reason, special consideration is needed in the magnetic analysis of cryogenic systems. When the excitation current is 10A, the normal spot appears on superconducting foil. The results of this analysis are calculated and compared with the experimental results. The linkage flux due to the excitation current of 10, 20, 30, 40 and 50A are respectively $1.30{\times}10-4$, $2.67{\times}10-4$, $5.08{\times}10-4$ and $6.15{\times}10-4Wb$.

• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 2002.05a
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• pp.125-128
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• 2002

The automotive industry have made an effort to reduce the weight of vehicle structures with increased safety, while initial model of the final product does not contain any prehistoric effects in a design stave. It takes lots of time to calculate forming effects that have great influences on the energy absorption of structures. In this paper, finite element inverse analysis is adopted to calculate forming effects, such as thickness variation and effective plastic strain as well as an initial blank shape with small amount of computation time. Crash analysis can be directly performed after inverse analysis of the forming process without remeshing scheme. The direct mesh mapping method is used to calculate an initial guess from the sliding constraint surface that is extracted from the die and punch set. Analysis results show that energy absorption of structures is increased with consideration of forming effects and finite element inverse analysis is usefully applicable to calculate forming erects of vehicle structures for the crash analysis.

• Steel and Composite Structures
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• v.42 no.2
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• pp.209-219
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• 2022

Offshore platforms in seismically active areas must be designed to survive in the face of intense earthquakes without a global structural collapse. This paper scrutinizes the seismic performance of a newly designed and established jacket type offshore platform situated in the entrance of the Gulf of Suez region based on the API-RP2A normalized response spectra during seismic events. A nonlinear finite element model of a typical jacket type offshore platform is constructed taking into consideration the effect of structure-soil-interaction. Soil properties at the site were manipulated to generate the pile lateral soil properties in the form of load deflection curves, based on API-RP2A recommendations. Dynamic characteristics of the offshore platform, the response function, output power spectral density and transfer functions for different elements of the platform are discussed. The joints deflection and acceleration responses demands are presented. It is generally concluded that consideration of the interaction between structure, piles and soil leads to higher deflections and less stresses in platform elements due to soil elasticity, nonlinearity, and damping and leads to a more realistic platform design. The earthquake-based analysis for offshore platform structure is essential for the safe design and operation of offshore platforms.

• The Journal of Korean Academy of Prosthodontics
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• v.44 no.5
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• pp.584-593
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• 2006

Statement of problem : Dental implant which has been developed gradually through many experiments and clinical applications is presently used to various dental prosthetic treatments. To conduct a successful function of implant prosthesis in oral cavity for a long time, it is important that not only structure materials must have the biocompatibility, but also the prosthesis must be designed for the stress, which is occurred in occlusion, to scatter adequately of load support. Therefore, it is essential to give the consideration about the stress analysis of supporting tissues for higher successful rates. Purpose : Recently, many implant manufacturing company produce various taper design of root form implant, the fixture is often selected. However, the stress analysis of taper form fixture still requires more studies. Material and method : This study we make the element models that five implant fixture; Branemark system(Nobel Biocare, Gothenberg, Sweden), Camlog system(Altatec, Germany), Astra system(Astra Tech, Sweden), 3i system(Implant Innovations Inc, USA), Avana system(Osstem, Korea) were placed in the area of mandibular first premolar and prosthesis fabricated, which we compared with stress distribution using the three-dimension finite element analysis under two loading condition. Results : This study compares the aspect of stress distribution of each system with the standard of Von mises stress, among many resulted from finite element analysis so that this research gets the following results. 1. In all implant system, oblique loading of maximum Von mises stress of implant, alveolar bone and crown is higher than vertical loading of those. 2. Regardless of loading conditions and type of system, cortical bone which contacts with implant fixture top area has high stress, and cancellous bone has a little stress. under the vertical loading, maximum Von mises stress is more higher in order of Branemark, Camlog, Astra, 3i, Avana. under the horizontal loading, maximum Von mises is more higher in order of Camlog, Branemark, Astra, 3i, Avana.

• Proceedings of the KSR Conference
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• 2011.10a
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• pp.693-696
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• 2011

The SRM (Switched Reluctance Motor) is composed of silicon steel plates where the rotor structure is simple and laminated without coil winding or permanent magnet, making it mechanically robust and its maintenance and repair excellent. Applying SRM as traction motor for railway vehicle is given consideration because of its ruggedness capability in severe loading condition and its compact structure. Optimal design of SRM is needed to reduce torque ripple to apply SRM for railway traction drive because SRM has high torque ripple. In this paper, switched reluctance motor with three different stator pole shapes is taken for magnetic analysis using 3d finite element method to apply SRM as traction drive for railway vehicle. It is observed that the model 3 added Tooth Tang Depth and Slot Round to stator shape gives the improved inductance and torque characteristic.

• Steel and Composite Structures
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• v.17 no.1
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• pp.83-103
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• 2014

The objective of this research is to study the ultimate moment capacity of the connections between steel I-beams and concrete-filled steel tube columns using different stiffener configurations. The main parameters considered are column cross section shape, square or circular, and filling the column with concrete. This analytical study includes finite element models using ANSYS program taking geometric and material nonlinearities into consideration. These models are verified against the experimental results obtained from previous researches and current design guides. The results show that using proper stiffener configuration affects the stress distribution through the connection and increases the ultimate moment capacity of the connections. Also, circular column is advantageous than the square column for all stiffener configurations and dimensions.

• Proceedings of the Korean Geotechical Society Conference
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• 1999.10a
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• pp.185-192
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• 1999

This paper presents the results of a parametric study on the behavior of tunnel face reinforced with horizontal pipes. A three-dimensional finite element model was adopted in this study to capture the three-dimensional nature of tunnel face behavior under various boundary conditions. A parametric study was peformed on a wide range of boundary conditions with emphasis on the effect of reinforcing layouts on the deformation behavior of tunnel face. The results of analysis such as tunnel face deformation behavior under various conditions were thoroughly analyzed, and a database for the behavior of tunnel face under different reinforcing conditions was established for future development of a semi-empirical design/analysis method for the tunnel face reinforcing technique. The results indicated that there exits an optimum reinforcing layout for a given tunnel condition, which must be selected with due consideration of tunnel geometry and ground condition.