http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
대표 교량을 이용한 국내 철근콘크리트 교량의 지진취약성 분석 방법
안효준,정성훈,신수봉 한국전산구조공학회 2019 한국전산구조공학회논문집 Vol.32 No.6
본 논문에서는 OpenSees 프로그램을 이용한 콘크리트 교량의 지진취약성 분석 방법에 대한 고찰을 제시한다. 교각 및 휨 부재 분산 비선형(distributed plasticity) 요소를 적용한 해석모델을 활용하여 지진에 대한 응답을 구하고 이를 통계적으로 처리하여 확률론적 지진취약성 분석을 수행한다. 응답 통계는 세기가 같은 지진파의 집단을 단계별로 scaling하는 stripe 방 법과 다양한 세기를 가진 지진파 집단을 선정하는 cloud방법을 적용하고 이 두 방법에 의한 분석결과의 차이를 비교한다. 한계 상태에는 교각의 휨변형과 교좌장치의 변위를 기준으로 산정한 다단계 한계상태를 적용하고, 여러 가지 한계상태를 취합한 시스템 취약성을 도출한다. 지진응답의 통계적 처리 방법과 교량의 손상 정의가 지진취약성 곡선에 주는 영향을 고찰한다. In this investigation, a set of seismic fragility curves for RC bridges in Korea is derived by considering variations of the representative analytical model. The dimensions and specifications of the model are determined, based on statistical analysis of the inventory of RC bridges in Korea. Variations of important modeling parameters such as material properties, size of structural members, and dimension of the bridge are defined based on statistical studies of the bridges. The OpenSees program is utilized for the analysis to represent the inelastic behavior of RC members. A systematic approach is developed to perform a large volume of inelastic dynamic analysis, in which continuous variation of the modeling parameters are programmed to appropriately represent the characteristics of RC bridges in Korea
안효준,박재형,송창현,이정익,김용희,김성중 한국원자력학회 2024 Nuclear Engineering and Technology Vol.56 No.3
In contrast to all-time flooded small modular reactor (SMR) systems, an in-kind flooding safety system (FSS) has been proposed as a passive safety system applicable to small modular reactors (SMRs) that adopt a metal containment vessel (MCV). Under transient conditions, the FSS can provide emergency cooling to dry reactor cavities and sustain long-term coolability using re-acquired evaporated steam in the reactor building on demand. When designing an FSS, the effect of the flooding flow area is vital as it affects the overall accident sequence and safety. Therefore, in this study, a MELCOR model of a reference SMR is developed and numerical analysis is performed under postulated accident scenarios. Without flooding, the MCV pressure of the reactor module exceeds the design pressure before core damage. To prevent core damage, an emergency flooding strategy is devised using various flow path parameters and requirements to ensure an adequate emergency coolant supply before the core damage is investigated. The results indicate that a flow area exceeding 0.02 m2 is required in the FSS to prevent MCV overpressure and core damage. This study is the first to report a strategic analysis for appropriately sizing an FSS flooding valve applicable to innovative SMRs.
안효준 국립경상대학교 공과대학 부설 첨단소재연구소 1994 尖端素材 Vol.4 No.-
In recent years a small sealed Ni/MH battery for cordless appliances has been extensively studied. The MH electrode characteristics were dependent on the fabrication method of alloys. The hydrogenation behavior of Ti-Ni powders prepared by mechanical alloying in a high energy ball mill have been investigaed by P-C-Isotherm curves, DSC(Differential Scanning Calorimetry), X-ray diffractometer, SEM(Scanning Elertron Microscope). Amorphous TiNi phase was formed 10 milling hours. The hydrogen storage capacity gradually decreased as a function of mechanical alloying time. There appears the DSC endothermic peak due to hydrogen evolution of amorphous hydride phase.
안효준 국립경상대학교 공과대학 부설 첨단소재연구소 1993 尖端素材 Vol.3 No.-
In order to study the phase changes of ErFe₂by hydrogenation reaction, static and cyclic hydrogenation were performed. During the static isothermal hydrogenation, an amorphous hydride phase is observed at about 200℃, and phase decomposition of stable hydride, ErH₂and Fe at 350℃. Hydrogen absorption-desorption cycling results in a decrease in the reversible hydrogen content with increasing number of cycles. As a result of degradation, amorphous of mixed ErH₂and Fe phases are formed. The heat of hydrogenation and repetitive strain induce a phase decompositiobn. Amorphous hydride phase formation as wel as binary stable hydride is one of the possible degradation mechanism of the metal hydride during cyclic operation.