• 유체기계공업학회:학술대회논문집
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• 유체기계공업학회 1998년도 유체기계 연구개발 발표회 논문집
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• pp.7-10
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• 1998

The pump safety related to the functions in nuclear power plants must be designed to meet load conditions considering seismic requirements. In order to satisfy both structural integrity and operability of these pumps, the initial step in the seismic qualification is to establish the resonant frequencies of the structure. Applications are made to the design of the vertical and horizontal type pump. Computational results are analyzed with respect to the dynamic characteristics and are compared to the expected design requirements.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2013년도 춘계학술대회 논문집
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• pp.1181-1182
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• 2013

• 한국소음진동공학회논문집
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• 제24권2호
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• pp.79-86
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• 2014

이 논문에서는 비상디젤발전기의 구조물 및 내부 회전체에 대한 건전성 평가를 위한 해석적 방법을 제시한다. 비상발전기는 원자력발전소 안전과 관련된 매우 중요한 기기로써 지진과 같은 비상사태에 원전의 안전 정지를 위한 관련 기기에 비상 전원을 공급한다. 비상발전기의 회전기 부분 또한 지진과 같은 충격에도 안전성을 확보해야 한다. 비상발전기 본체에 대한 모달 해석을 하여 공진 주파수가 지진 주파수 영역에 있는지를 확인하여 응력 해석의 방법을 정했다. 회전체 부분의 안전성은 저널 베어링의 필름 두께와 임계 회전수를 계산하여 최소 유막 요구치와 운전속도와 비교하여 안전성을 판단하였다. 계산된 응력해석의 최대치는 허용치보다 작았으며, 저널 베어링의 유막과 회전수 또한 안전한 범위에 들었다. 이 논문에서는 저널 베어링의 안전해석에 지진하중을 정적 하중으로 보았으나 향후 연구에 있어서는 지진하중의 동적 특성을 회전체에 적응하는 새로운 해석적 방법의 개발이 필요할 것으로 사료된다.

• 한국전산구조공학회:학술대회논문집
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• 한국전산구조공학회 2001년도 봄 학술발표회 논문집
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• pp.481-488
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• 2001

The HANARO in-chimney bracket was proposed as a structure which supports the guide tubes of irradiation facilities at the irradiation sites of CT, IR and OR4/5 in HANARO core for the reduction of flow-induced vibration and seismic response of the irradiation facilities. For the evaluation of the structural integrity of the in-chimney bracket, its finite element model is developed. The seismic response analysis was performed for the in-chimney bracket and related reactor structures, under the response spectrum of OBE and SSE. The analysis results show that stress values of the in-chimney bracket and reactor structures for the seismic loads are within the ASME code limits. It is also confirmed that its fatigue usage factor is much less than 1.0. For the verification of the implementation effects of the in-chimney bracket, the vibration level of the guide tube of the instrumented fuel assembly, which is subjected to fluid-induced vibration, was measured and analyzed. The vibration analysis results demonstrate that the vibration level of the instrumented fuel assembly has been remarkably reduced after installing the in-chimney bracket. Therefore, when the in-chimney bracket is installed at the reactor chimney, any damage on the structural integrity is not expected.

• Nuclear Engineering and Technology
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• 제55권5호
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• pp.1577-1586
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• 2023

Safety qualification of a steam generator is a crucial issue related to faulted condition design loads, including earthquake loads, and it should be ensured that the structural integrity of a steam generator does not exceed its design load. Using data from the Gyeongju and Pohang earthquakes, the two most powerful recorded seismic events in Korea, seismic analyses of a typical steam generator are conducted in this study. The modal characteristics are used to develop an input deck for these analyses. With a time history analysis, the responses of the steam generator in the event of an earthquake are obtained. In particular, the displacement, velocity, and acceleration responses are obtained in the time domain, with these outcomes then used for a detailed structural analysis as part of the ensuing assessment. The response spectra are also generated to determine the response characteristics in the frequency domain, focusing on the response comparisons between the Gyeongju and Pohang earthquakes. Structural integrity can be ensured by performing additional analysis using results obtained from the time history analysis considering the input excitations of various earthquakes considered in the design.

• Earthquakes and Structures
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• 제26권3호
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• pp.191-201
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• 2024

A comprehensive probabilistic seismic hazard analysis was carried out in Istanbul to examine the seismotectonic features of the region. The results showed that earthquakes can trigger one another, resulting in the grouping of earthquakes in both time and space. The hazard analysis utilized the Poisson model and a conventional integration technique to generate the hazard curve, which shows the likelihood of ground motion surpassing specific values over a given period. Additionally, the study evaluated the impact of seismic hazard on the structural integrity of an existing masonry tower by simulating its seismic response under different ground motion intensities. The study's results emphasize the importance of considering the seismotectonic characteristics of an area when assessing seismic hazard and the structural performance of buildings in seismic-prone regions.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2009년도 추계학술대회 논문집
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• pp.472-472
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• 2009

The safety of cultural properties, medical treatment and electrical communication equipments in a building was hardly considered against the earthquake induced vibration, while the integrity of the building structure has been taken into account through the resistant earthquake design. This paper presents design of a seismic isolation table for both indoor and outdoor electrical communication equipment. First of all, artificial earthquake waves compatible with floor and ground response spectra for electrical communication equipments are generated using previously recorded seismic waves. Two kinds of one-degree-of-freedom seismic isolation table systems: spring-linear damper and spring-friction damper systems are considered and their responses to artificial earthquake waves are simulated. Design parameter study for two seismic isolation tables are performed through simulations and a seismic isolation table for both indoor and outdoor electrical communication equipment is designed considering the simulation results.

• 한국지반공학회논문집
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• 제21권4호
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• pp.51-63
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• 2005

콘크리트 포장에는 재료의 결함이나 구조적 문제점으로 인하여 표면균열, 슬래브의 처짐 등과 같은 문제가 발생할 수 있다. 결함이 발생한 콘크리트 포장이 현재 운용중일 때 심각한 교통문제와 경제적 손실을 초래하지 않기 위해서는 신속하게 유지관리가 이루어져야 한다. 이러한 콘크리트 포장의 신속한 유지관리를 위해서 탄성파 기법이 효율적으로 활용될 수 있는데, 이는 탄성파 기법으로 재료의 공학적 물성과 건전도 상태를 비파괴적, 비관입적으로 신속하게 측정할 수 있고, 또한 콘크리트 하부 기층, 보조기층, 노반의 강성까지 측정할 수 있는 장점을 가지고 있기 때문이다. 본 연구에서는 건전도 평가기법으로서 비파괴 탄성파 기법의 적합성을 평가하기 위하여 탄성파 기법에 관한 수치해석을 수행하였고, 수치해석 결과를 근간으로 하여 콘크리트 활주로의 재료적 결함, 구조적 건전도 상태를 종합적으로 평가하는 비파괴기법 평가체제를 제안하였다. 표면균열이 국부적으로 발달한 $\bigcirc\bigcirc$ 콘크리트 활주로에 대하여 본 연구에서 제안한 평가체제를 적용하여 표면균열의 원인을 규명하였다. 탄성파 건전도 평가로 획득한 활주로의 건전도 상태는 현장에서 채취한 코어와 코어시험 결과를 이용하여 비교함으로써 본 연구에서 제안한 비파괴 탄성파 기법 평가체제의 신뢰성을 확인하였다.

• Journal of Mechanical Science and Technology
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• 제14권2호
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• pp.215-225
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• 2000

The structural integrity of the fuel test loop (FTL) in a Korean experimental reactor is evaluated when the FTL, submerged in a water environment, is subjected to a postulated pipe rupture. The analyses are performed under static and dynamic conditions, imposing the thrust force history at each postulated pipe rupture section. Through analysis the following results are found: l) A double ended guillotine can not be expected based on the toughness of the material, 2) the structural integrity of the chimney surrounding the FTL would not impede the structural integrity by the pipe whip. All analyses are performed by finite element methods.

• Structural Engineering and Mechanics
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• 제82권4호
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• pp.417-434
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• 2022

In this work, a review of mechanical metamaterials and seismic protection systems that use them is carried out, focusing on passive protection systems. During the last years, a wide variety of classical systems of seismic protection have demonstrated to be an effective and practical way of reducing the seismic vulnerability of buildings, maintaining their health and structural integrity. However, with the emergence of metamaterials, which allow obtaining uncommon mechanical properties, new procedures and devices with high performance have been developed, reducing the seismic risk through novel approaches such as: seismic shields and the redirection of seismic waves; the use of stop band gaps and the construction of buried mass resonators; the design of pentamodal base isolators. These ideas are impacting traditional areas of structural engineering such as the design and building of highly efficient base isolation systems. In this work, recent advances in new seismic protection technologies and researches that integrate mechanical metamaterials are presented. A complete bibliometric analysis was carried out to identify and classify relevant authors and works related with passive seismic protection system based on mechanical metamaterial (pSPSmMMs). Finally, possible future scenarios for study and development of seismic isolators based on mechanical metamaterials are shown, identifying the relevant topics that have not yet been explored, as well as those with the greatest potential for future application.