• Earthquakes and Structures
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• 제13권3호
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• pp.299-307
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• 2017

High Damping Rubber bearings (HDR bearings) have been used in the seismic design of bridge structures widely in China. In earthquakes, structural natural periods will be extended, seismic energy will be dissipated by this kind of bearing. Previously, cyclic loading method was used mainly for test studies on mechanical properties of HDR bearings, which cannot simulate real seismic responses. In this paper, Real-Time Substructure (RTS) test study on mechanical properties of HDR bearings was conducted and it was found that the loading rate effect was not negligible. Then the influence of peak acceleration of ground motion was studied. At last test results were compared with a numerical simulation in the OpenSees software framework with the Kikuchi model. It is found that the Kikuchi model can simulate real mechanical properties of HDR bearings in earthquakes accurately.

• 한국문헌정보학회지
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• 제54권2호
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• pp.247-267
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• 2020

도서관은 정보유통을 담당하는 사회적 공기이다. 도서관은 재난상황에서도 사회 통합에 기여할 수 있도록 서비스 제공의 지속가능성을 확보할 필요가 있다. 최근 발생한 코로나 19 바이러스의 확산에 따라 감염을 예방하기 위해 도서관을 폐쇄하고 이용자의 방문을 중단시킨 바 있다. 본고는 예상치 못한 재난 상황에서의 국내외 도서관계의 대응을 살펴보고 지속가능성을 확보할 수 있는 서비스 방안과 방안 수립시의 고려해야할 기본원칙을 제시하였다.

• 한국정보통신학회:학술대회논문집
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• 한국정보통신학회 2019년도 춘계학술대회
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• pp.296-297
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• 2019

대형 재난이나 사이버 위기 발생 시에 조기에 대응할 수 있는 효율적인 위기관리체계가 조직 내에서 뿐만 아니라, 협력기관 및 외부와의 관계에서도 필요하다. 본 논문에서는 대형 재난이나 사이버 위기 발생 시에 대처하는 국내외 대응 현황을 살펴보고, ICT 기술발전과 더불어 새롭게 나타나는 위기 대응의 문제점과 앞으로의 전망에 대해 고찰하고자 한다.

• 한국공간구조학회논문집
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• 제21권2호
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• pp.57-66
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• 2021

This study develops finite element models for seismically-deficient reinforced concrete building frame retrofitted using fiber-reinforced polymer jacketing system and validates the finite element models with full-scale dynamic test for as-built and retrofitted conditions. The bond-slip effects measured from a past experimental study were modeled using one-dimensional slide line model, and the bond-slip models were implemented to the finite element models. The finite element model can predict story displacement and inter-story drift ratio with slight simulation variation compared to the measured responses from the full-scale dynamic tests.

• Structural Engineering and Mechanics
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• 제83권1호
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• pp.31-43
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• 2022

A nonlinear gas-spring tuned mass damper is proposed to mitigate the seismic responses of the multi-degree-of-freedom (MDOF) structure, in which the nine-story benchmark model is selected as the controlled object. The nonlinear mechanical properties of the gas-spring are investigated through theoretical analysis and experiments, and the damper's control parameters are designed. The control performance and damping mechanism of the proposed damper attached to the MDOF structure are systematically studied, and its reliability is also explored by parameter sensitivity analysis. The results illustrate that the nonlinear gas-spring TMD can transfer the primary structure's vibration energy from the lower to the higher modes, and consume energy through its own relative movement. The proposed damper has excellent "Reconciling Control Performance", which not only has a comparable control effect as the linear TMD, but also has certain advantages in working stroke. Furthermore, the control parameters of the gas-spring TMD can be determined according to the external excitation amplitude and the gas-spring's initial volume.

• 한국농공학회논문집
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• 제48권7호
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• pp.45-52
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• 2006

A cyclic viscoelastic-viscoplastic constitutive model for clay is incorporated into an effective stress based seismic response analysis to describe viscous effect of clay layer to sand layer during earthquake. The seismic response against main shock of 1995 Hyogoken Nambu Earthquake is analyzed in the present study. Acceleration responses in both clay layer and just upper liquefiable sand layer are damped due to viscous effect of clay. A cyclic viscoelastic-viscoplastic constitutive model for clay was implemented into a FEM code, and $Newmark{\beta}$ method was employed for the time discretization in the finite element formulation. Seismic responses were simulated by numerical method with recorded data at Port Island, Kobe, Japan. As results of this study, it was found that a cyclic viscoelastic-viscoplastic constitutive model can give good description of dynamic behavior characteristics including viscoelastic effect.

• Structural Engineering and Mechanics
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• 제54권2호
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• pp.221-237
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• 2015

An integrated method is proposed for structural nonlinear damage detection based on time series analysis and the higher statistical moments of structural responses in this study. It combines the time series analysis, the higher statistical moments of AR model residual errors and the fuzzy c-means (FCM) clustering techniques. A few comprehensive damage indexes are developed in the arithmetic and geometric mean of the higher statistical moments, and are classified by using the FCM clustering method to achieve nonlinear damage detection. A series of the measured response data, downloaded from the web site of the Los Alamos National Laboratory (LANL) USA, from a three-storey building structure considering the environmental variety as well as different nonlinear damage cases, are analyzed and used to assess the performance of the new nonlinear damage detection method. The effectiveness and robustness of the new proposed method are finally analyzed and concluded.

• 수산해양기술연구
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• 제36권4호
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• pp.337-346
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• 2000

Earthquake is a natural disaster accompanied by damage of human and properties caused by the ground motion, crustal movements, faults as well as tidal wave. The earthquake is known to occur mostly in earthquake-prone areas and the Korean Peninsula is known to be relatively safe in terms of geological characteristics. In order to withstand on severe environmental dynamic random load such as an earthquake, the large structure need to be designed to withstand the anticipated seismic tremor. The seismetic design is essential for building structures, bridges, and large structures which is handles explosive gases. Thus, the necessity of earthquake resistant analysis for large structure is growing and the capability of dynamic analysis should be obtained. In this thesis, dynamic responses of a high building(height 60m, width 18) which subjected to random earthquake load are presented which responses are derived using dynamic analysis methods such as response spectrum analysis, mode superposition and direct integration. Each results are also compared to review the merit of each methods.

• 국제초고층학회논문집
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• 제10권3호
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• pp.229-242
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• 2021

Dynamic characteristics of tall building structures with double negative stiffness damped outriggers (2NSDO) are parametrically studied using the theoretical formula. Compared with one negative stiffness damped outrigger (1NSDO), 2NSDO can achieve a similar maximal modal damping ratio with a smaller negative stiffness ratio. Besides, the 2NSDO can improve the maximum achievable damping ratio to about 30% with less consumption of an outrigger damping coefficient compared with the double conventional damped outriggers (2CDO). Besides, the responses of structures with 2NSDO under fluctuating wind load are investigated by time-history analysis. Numerical results show that the 2NSDO is effective in reducing structural acceleration under fluctuating wind load, being more efficient than 1NSDO.

• 한국콘텐츠학회논문지
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• 제14권11호
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• pp.644-656
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• 2014

최근 들어 이어지는 대형 안전사고는 공공 및 민간 영역에 걸쳐 발생하는 가운데, 초동 대처의 부실로 인해 많은 인명과 재산의 손실을 가져오고 있다. 부지불식간에 비상사태가 발생할 경우 신속한 신고 접수 및 정확한 현장 상황 전파와 같은 초기 대응만 제대로 이루어진다면 그 피해를 최소화할 수 있다. 이러한 안전사고와 재난 재해로부터 선제적 대응 및 예방에 스마트폰 기반 모바일 재난관련 앱의 역할이 중요해지고 있다. 이러한 관점에서 본 연구는 재난에 효과적으로 대처하기 위해 개발된 국내 재난관련 공공 앱서비스의 현황 및 이용 실태를 조사하였다. 재난 안전 분야 공공 앱은 보급 초창기로 사용자들에게 어떠한 요인이 앱 서비스의 이용에 중요한 영향을 미치는지를 밝히고자 하였다. 이를 토대로 현재 운용중인 재난관련 공공 앱의 문제점과 개선 방향을 제시하고, 향후 개발되어질 공공 앱의 서비스 방향과 이용 활성화 방안을 모색하고자 하였다. 연구결과, 사용자 측면의 신속성과 콘텐츠 측면의 신뢰도가 재난앱 활성화를 위해 가장 시급하고도 중요도 높은 요인으로 도출되었다.