• Journal of the Computational Structural Engineering Institute of Korea
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• v.31 no.5
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• pp.215-226
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• 2018

In this paper, to estimate the dynamic behavior of a submerged floating tunnel(SFT) by underwater explosion(UE), the SFT is modeled and analyzed by the explicit structural analysis package LS-DYNA. The section of SFT near to explosion point is modeled to shell and solid elements using elasto-plasticity material model for concrete tubular section and steel lining. And the other parts of the SFT are modeled to elastic beam elements. Also, mooring lines are modeled as tension-only cable elements. Total mass of SFT is including an added mass by hydrodynamic effect. The buoyancy on the SFT is considered in its initial condition using a dynamic relaxation method. The accuracy and the feasibility of the analysis model aree verified by the results of series of free field analysis for UE. And buoyancy ratio(B/W) of SFT, the distance between SFT and an explosion point and the arrangement of mooring line aree considered as main parameters of the explosion analysis. As results of the explosion analysis, the dynamic responses such as the dent deformation by the shock pressure are responded less as more distance between SFT and an explosion point. However, the mooring angle of the diagonal mooring system can not affect the responses such as the horizontal displacement of SFT by the shock pressure.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.33 no.1
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• pp.47-59
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• 2013

Ultimate load factors of PPWS(Prefabricated Parallel Wire Strand) sockets in main cables of suspension bridges are studied with respect to the tapered angles of the inner surface of sockets. After briefly reviewing the current design method, 15 numbers of finite element models of sockets are prepared by varying the number of wires in a strand and the tapered angles. The finite element models are updated by comparing experimental and numerical results, so that the models can reflect the real behavior of sockets. The stress distributions at the first yielding and ultimate states are analyzed by performing the incremental load analysis using ABAQUS. It is concluded that the optimized tapered angle of sockets should be determined at the specific angle between the results of verification equations of the required bonding length and stress resistance length.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.18 no.1
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• pp.79-91
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• 2005

The behaviors and design procedures of wale in innovative prestressed support(IPS) system are presented in this paper. Using the theory of the beam on elastic foundation, the member forces of the wale under initial pretension are evaluated. Choosing cable tensions as redundant forces, member forces subjected to earth pressure are calculated by the statically indeterminate analysis. The computer analysis model under uniform and non-uniform earth pressure is constructed using beam element for the IPS wale, tension-only element for cable, and compression-only element for soil. Axial forces and bending moments of IPS wale under initial pretension and design earth pressure are calculated. The combined stresses due to these axial force and bending moment are estimated to satisfy the design formula.

• Archives of design research
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• v.16 no.2
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• pp.365-374
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• 2003

Recently many TV have much interest in Network Design to get an advantage in the competition of the multi channels as part of the channel brand strategy. Since the Network Design was introduced in Korea in 1997, the major cable channels and satellite channels began to display Network Design on their screen competitively. But the production of Network Design has many problems in the field due to the lack of research information. The style guide is considered very important to succeed in Network Design execution as an indispensible process for a consistent planning and concrete production. This paper studied the Network Design Style Guide to establish a theoretical system of Network Design for a TV channel image promotion. First, this paper discussed the concept of Network Design and the necessity of the Network Design Style Guide, Second, this paper systemized the main component through the case study of the Network Design Style Guide and defined the concept of each element.

• Journal of Korean Society of Steel Construction
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• v.12 no.5 s.48
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• pp.581-593
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• 2000

In this study, vertical dynamic analyses on the suspension bridges under seismic load are developed. Time domain analysis, random vibration analysis, and spectral analysis are formulated theoretically. The random nitration analysis is checked by numerical integration and the mathematical integration with correlation coefficient which include CQC and SRSS method in the conditions of white noise and filtered white noise. Beam, truss and frame elements are used in order to model the suspension bridge. Geometric stiffness due to dead load is considered for cable and tower.

• The Journal of the Korea institute of electronic communication sciences
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• v.2 no.1
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• pp.40-45
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• 2007

The repeaterless system can be designed by applying EDFA technology in receiver, transmitter and optical cable in the case of connecting several hundred km from coast to coast, between continents or islands. Because of no repeater the repeaterless system do not need power system to feed laser diode in repeater for signal amplification and cooper tuber in submarine cable. So we can be configured more reliable and economical compared to repeater system. But lower loss optical fiber must be used to get enough signal amplitude without the amplification of repeater. This report consider long distance optical repeaterless system by reflecting the limitation factor of optical amplification.

• Proceedings of the KIEE Conference
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• 2011.07a
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• pp.2148-2149
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• 2011

환경오염에 대한 규제가 강화됨에 따라 친환경자동차의 개발과 보급이 활발하게 이루어지고 있기 때문에 전기에너지를 구동에너지로 사용하는 전기자동차의 보급을 위한 필수 요소인 전기자동차 충전 설비의 보급이 지속적으로 증가하고 있고 있지만, 전기자동차 충전설비의 안전성 확보를 위한 제도가 확립되어 있지 않은 상태에서 시범 보급되고 있는 현실이다. 따라서, 본 연구에서는 국내외 전기자동차 및 전기자동차 충전전원 공급설비관련 기준 및 표준 분석을 통하여 현재 전기설비기술기준 및 판단기준에 명시된 내용 분석을 통하여 전기자동차 충전전원 공급설비에 대한 안전성 확보를 위한 충전기, 충전케이블, 커플러 등의 시설기준에 대하여 나타내었다. 본 연구결과에 대한 활용에 따른 전기자동차 충전설비의 안전성 확보로 전 세계적인 기후변화 대응과 우리나라의 저탄소 녹색성장정책에 대응하기 위한 스마트그리드 산업의 활성화에 기여하고자 한다.

• Journal of the Earthquake Engineering Society of Korea
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• v.1 no.3
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• pp.45-58
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• 1997

An analysis algorithm and a computer program have been developed to clarify the geometrically nonlinear response characteristics of a suspension bridge subject to the support excitation. The Finite Element procedures are utilized for the application to a self-anchored suspension bridge or to a mono-duo cable suspension bridge. The propagation of earthquake wave is simulated by taking a record as the input at the left anchorage of the bridge, and addign appropriate time delay to the other inputs for the purpose of considering the multi-support effects. According to the application for a mono-duo self-anchored suspension bridge, it has been found that the effects of nonlinear behavior and multi-support excitation are notable for this relatively short-spanned suspension bridge.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.9 no.1
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• pp.11-23
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• 1989

This paper presents the results of the numerical analysis on the behaviour of mooring system of offshore guyed tower. Finite element method is used and geometric nonlinearities are considered in the analysis of mooring line. The governing equilibrium equations are derived by the principle of virtual work, and modified Newton-Raphson method and Newmark-${\beta}$ method are employed in response calculations. The drag and inertia effects of fluid are included using a Morrison type equation. The influences of changing typical parameters like initial inclination and tension of line at the guy attachment point, the length of clump weight, its unit weight and the anchor line length are examined. The effects of idealising the clump weight as a point load(lumped clump weight) on the behaviour of mooring lines are also discussed. Numerical examples demonstrate the validity and capability of the mathematical formulation.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2006.06a
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• pp.79-80
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• 2006

본 논문에서는 초고압전력용 케이블에서 절연재료로 사용되고 있는 가교폴리에틸렌 내부(XLPE)에 침투된 침전극의 기울기변화에 따른 XLPE의 전계분포를 경계요소법에 의한 3차원 시뮬레이션 프로그램을 통하여 해석하여, 약 $20^{\circ}$의 기울기에서 전계가 집중되는 현상을 확인하였다.