본 연구에서는 옹벽 구조물의 내진성능 평가를 위해 2차원 유한요소 해석을 수행하였다. 2차원 유한요소 모델은 실제로 시공된 옹벽 구조를 기반으로 2차원 평면변형 요소로 모델링되었으며, 지반은 각각 유한요소와 무한요소로 모델링 하였다. 지진하중은 총 38개의 인공 지진을 생성하여 사용하였고, 생성된 인공 지진파를 11개의 PGA로 나누어 총 418회의 시간이력해석을 수행하였다. 수치해석 결과를 바탕으로 옹벽 구조물의 지진에 대한 취약도를 분석하였다. 취약도 분석 결과 콘크리트 및 철근의 취약도 곡선이 낮은 PGA 수준에서 급격히 변하는 것을 관찰할 수 있었다. 유한요소 해석 결과를 바탕으로 실제 현장의 옹벽 구조에서 상대적으로 낮은 수준의 지진파가 발생하더라도 높은 파괴확률로 인해 지진에 상대적으로 취약함을 확인하였다.

Experimental evaluation of torsional behavior, which is possible behavior of seismic beams of RC structures, was carried out. Concrete strength and stirrup spacing were set as experimental variables to investigate the torsional strength of RC beams. Based on the experimental results, the torsional strength of RC beams was compared and analyzed. From the experimental results, the concrete strength was caused a difference of about 30% in the torsional strength of the maximum torque of the RC beam specimen, and the stirrup spacing was found to be about 2.8 times and 5 times that of the peak torque. Therefore, this study will be an important study to understand the effect of both concrete strength and stirrup spacing for the torsional strength or torsional behavior of RC beams.

In recent years, the number of earthquakes has increased worldwide. There has been an extreme increase on the Korea Peninsula, which is considered a safety zone for earthquakes. In particular, in the event of earthquakes, most structures on the Korea Peninsula are severely damaged, because most are not designed to withstand them. Damage to and destruction of civil structures, such as bridges, nuclear facilities, and dams, is worse than that of other structures. It is necessary to evaluate and predict the extent of damage by earthquake magnitude, as the magnitude of earthquakes is increasing as well as the frequency. A major feature of the occurrence of earthquakes is uncertainty. For this reason, it is necessary to adopt a stochastic approach, and studies using this approach are increasing. However, although there have been several studies on bridges and nuclear facilities, there have been few studies on probabilistic seismic risk evaluation for multi-functional weirs. Thus, this study presents 3D multi-functional weirs and performs a time history analysis by using LS-DYNA, a general structure analysis program. Probabilistic seismic fragility assessment is conducted by Monte Carlo simulation.

Torsional constants of both rectangular cross section and circular cross section are induced by exact solution, and was easy to calculate since of simple shape. However, it is very difficult to calculate the torsional constant of both an arbitrary cross-section and a composite cross-section. In this study, a finite element formulation was proposed as a method to calculate the torsional constant of both an arbitrary cross-section and a composite cross-section. From the numerical study, numerical results was compared with exact solution.

In this study, finite element analysis of korean precast concrete panels was performed and 3D infinite element modeling was used. Infinite elements can be formulated in time domain and nonlinear behavior analysis is possible. Based on the numerical results, the performance of the packing layer of korean precast concrete panels was examined.

Numerical behavior of FRP(Fiber Reinforced Polymer) panel in steel frame structure was evaluated through the finite element analysis in this study. In order to numerical analysis, a experimental test results was used to develop a three dimensional finite element model of steel frame specimen. Numerical results of the steel frame specimen was well predicted the experimental behavior of steel frame specimen. Based on the developed three dimensional finite element model of steel frame specimen, the behavior of FRP panel in the steel frame specimen was evaluated. From the numerical analysis results, strength of the steel frame specimen with FRP panel was governed by FRP panel. Also, diagonal compression behavior governed the FRP panel in the steel frame specimen in the numerical analysis results.

Two steel-frame joint specimens with welding joint parts were constructed and evaluated. Two types of displacement load, monotonic and cyclic, were used to evaluate the steel-frame joint specimens. According to the experimental results, the maximum moment of the cyclic test results was 80% smaller than that of the monotonic test results. Local buckling was observed in the compression area of the H-beam flange. A finite element analysis model based on the experimental results was proposed to analyze the steel-frame joint specimens. The numerical results predicted the experimental behavior of the steel-frame joint specimens well. Therefore, it is possible to use the proposed finite element analysis model to evaluate middle- and low-rise steel-frame buildings constructed in South Korea.

The number of earthquakes is increased recently. A electrical equipment is very important in all electric system because it can make a serious problems in such as nuclear power plants like a black out. So, seismic safety design of electrical equipment is necessary to keep to use the convenience of electronics. In this study, threshold values of electronic equipment was founded out from the numerical results by using seismic load.

A behavior of FRP(Fiber Reinforced Polymer) panel in a steel frame structure was evaluated through the finite element analysis in this study. In order to numerical analysis, a experimental test results was used to develop a three dimensional finite element model of steel frame specimen. Numerical results of the steel frame specimen was well predicted the experimental behavior of steel frame specimen. Based on the developed three dimensional finite element model of steel frame specimen, the behavior of FRP panel in the steel frame specimen was evaluated. From the numerical analysis results, strength of the steel frame specimen with FRP panel was governed by FRP panel. Also, diagonal compression behavior governed the FRP panel in the steel frame specimen in the numerical analysis results.

Abstract: In this study, finite element analysis modeling is proposed to evaluate middle- and low-rise steel-frame buildings constructed in South Korea. Two steel-frame joint specimens with welding joint parts were constructed and evaluated. Two types of displacement load, monotonic and cyclic, were used to evaluate the steel-frame joint specimens. According to the experimental results, the maximum moment of the cyclic test results was 80% smaller than that of the monotonic test results. Local buckling was observed in the compression area of the H-beam flange. A finite element analysis model based on the experimental results was proposed to analyze the steel-frame joint specimens. The numerical results predicted the experimental behavior of the steel-frame joint specimens well. Therefore, it is possible to use the proposed finite element analysis model to evaluate middle- and low-rise steel-frame buildings constructed in South Korea.

In korea, only small amount of nonstructural lightweight concrete is being used through indirect effects such as heat insulation property and soundproofing rather than structural elements due to lack of structural lightweight aggregates and lack of understanding about lightweight concrete development, etc. That`s why structural lightweight concrete to reduce weight has not been put to practical use. This study is a part of high strength lightweight aggregate concrete researches using lightweight aggregates and the purpose of this study is to find out the basic physical characteristics and tension cracking fracture characteristics of lightweight concrete. Crack Mouth Opening Displacement is measured through 3 point flexure experiment about notch beam. Load-CMOD characteristics are examined through rules of countries, characteristics of lightweight concrete and tension cracking fracture experiments. The degree of tensile characteristic alteration according to size changes of specimen and the characteristics about crack surface are analyzed. The changes of softening curve are analyzed and fracture energy is drawn through inverse analysis by the obtained Load-CMOD curve. To decide fracture energy and analysis parametric, inverse analysis is conducted and Ant Colony Method is conducted for optimization and then a way to find out optimal parameterization fracture energy is suggested.

Earthquakes is impossible to predict and occur within very little or no warning. They cause significant damage to property and inflict large human casualties. Seismic retrofit for non-seismic design RC frame has been studied over the years. Although there are many seismic retrofit methods, the seismic retrofit methods are increased weight and physical damage to structures. This study evaluates the seismic performance of RC frame retrofitted with velcro. The specimens were made scale down of actual steel structures, and displacement loads were applied in the trasnverse direction.

It has been many efforts for reinforcement of existing structure since the number of earthquake has been increased world widely. Especially the occurrence of earthquake surrounding area of Korean peninsular is dramatically increased. Since the buildings in Korea have not been designed to carry the lateral and shear force caused by earthquake, the building will experience massive damages even under moderate earthquake. For this reason, the viscoelastic damper is proposed in this paper to enhance the earthquake resistance of a steel frame buildings. The viscoelastic dampers have been able to increase the overall damping of the structure significantly, hence improving the overall performance of dynamically sensitive structures. In this paper, Viscoelastic dampers designed are consists of FRP panel and viscoelastic material. In this paper, evaluate the performance of the viscoelastic damper through the experiment.

Since it is impossible to predict earthquakes, they involve more casualties and property damage compared to meteorological disasters such as heavy snow and heat waves, which can be predicted through weather forecasts. This has highlighted the need for seismic design and reinforcement. Recently, the use of composite materials as reinforcement has surged because steel plate reinforcement and section enlargement are likely to result in increased weight and physical damage to structures. This study evaluates the seismic performance of panels created from composite materials, and their guide systems. The specimens were miniature versions of actual steel structures, and displacement loads were applied in the transverse direction. Seismic performance was found to improve when structures were reinforced with seismic panels.

Compared to steel of the same weight in steel concrete structures, fiber reinforced polymer (FRP) is known to have greater strength and better resistance to corrosion. As such, it is being proposed as an effective structural material. Despite its many advantages, FRP has not been rapidly adopted in civil structures. This is because it is more expensive, prone to brittle fracture, and has weak fire resistance. To examine changes in the mechanical properties of FRP and the effectiveness of fire resistant coating, this study conducted tensile tests on coated and uncoated specimens over varying temperature. Glass fiber has excellent fire resistance since it does not melt or burn at high temperatures. However, epoxy is unable to withstand exposure to temperatures exceeding the transition temperature, thus leading to unsatisfactory structural performance and fire resistance. This study investigated the behavioral changes in FRP by exposing the specimens to temperatures ranging from room temperature (approx. 25℃) to 300℃, so as to improve the fire resistance of epoxy.

Because earthquakes occur within very little or no warning, they cause significant damage to property and inflict large human casualties. Seismic design and reinforcement has been extensively studied over the years, for the purpose of reducing damage from earthquakes. Composite materials are being widely used as reinforcement because the use of steel plates and section enlargement are time-consuming methods that leave physical damage to structures. This study assessed the guide system performance of FRP panels created from composite materials. Actual steel structures were reproduced in miniature form, and were subjected to transverse displacement loads. The experiments were carried out by applying two types of FRP panel guide systems to the specimens.

This study is a part of high strength lightweight aggregate concrete researches using lightweight aggregates and the purpose of this study is to find out the basic physical characteristics and tension cracking fracture characteristics of lightweight concrete. Crack Mouth Opening Displacement is measured through three point flexure experiment about embellish notch beam. Load-CMOD characteristics are examined through rules of countries, characteristics of lightweight concrete and tension cracking fracture experiments. The degree of tensile characteristic alteration according to size changes of specimen and the characteristics about crack surface are analyzed. The changes of softening curve are analyzed and fracture energy is drawn through inverse analysis by the obtained Load-CMOD curve. To decide fracture energy and analysis parametric, inverse analysis is conducted and Ant Colony Method is conducted for optimization and then a way to find out optimal parameterization fracture energy is suggested.

정부는 1999년부터 국가적으로 보존 및 이용가치가 높은 학술, 문화, 과학기술, 행정 등에 관한 공공정보를 체계적으 로 수집하고 디지털데이터로 구축하는 국가DB 사업을 추 진해 왔다. 그러나 기구축한 국가DB는 부처 또는 전문영역 별 DB 포맷(format)과 설계표준이 상이하고, 정보제공자 위주의 정보로 가공되어 정부3.0의 공공정보 개방과 창의적 활용에 대응하기 어려웠다. 이에 대안으로 제시된 것이 개 방형 연결데이터인 Linked Open Data(LOD)이다. LOD는 기존의 HTML(HyperText Markup Language)로 제공되었 던 데이터를 RDF(Resource Description Framework)형식 의 의미적 연관 관계있는 온톨로지(Ontology) 정보로 변환 시켜 URI(Uniform Resource Identifier)를 통해 웹상에 공 개하여 누구나 제약 없이 쉽게 사용할 수 있다는 장점이 있다. 또한, 여러 기관에서 생성한 데이터를 상호 관련성이 높은 정보와 연결되어 거대한 지식베이스(knowledge base) 구현에 적합하다. 본 연구는 국립중앙과학관과 국립수목원이 공동으로 구 축한 LOD와 국내외 LOD구축 사례를 소개하고 기존의 DB 공개 방식과 LOD의 차이점을 비교하여 기존 DB를 LOD형 태로 변환했을 때의 장점과 해결해야할 문제점 등을 고찰해 보고자 하였다. LOD는 기존의 문서(Document)중심의 웹에서 데이터 (Data)중심의 웹으로 온톨로지를 통한 Data의 의미적 연결 성을 확보하여 인간과 기계간의 상호소통뿐만 아니라 컴퓨 터 간에도 스스로 추론하여 의미 있는 정보를 추출할 수 있다. 또한 LOD는 URI와 RDF를 사용하여 기존 DB에 비 해 개방성과 유연성이 좋으며, 다른 데이터와 서로 링크하 여 데이터 매시업(Mashup) 및 재사용이 유용하다. LOD구축사업은 국립중앙과학관과 국립수목원에 기 구 축된 생물다양성 정보를 RDF형태로 변환하여 두 기관의 정보를 연결하고 관련정보의 공동검색 그리고 그와 관련된 연관정보를 구축하였다. 또한 다른 기관과의 정보 연결까지 고려한 ‘LOD플랫폼’ 및 ‘LOD생물다양성정보통합시스템’ 을 구축하고 생물다양성정보의 통합 지식베이스의 기틀을 마련하였다. LOD플랫폼은 LOD발행·관리·통계, 데이터브라우징, SPARQL Endpoint, 검색, 다운로드 등의 기능을 구현하였 으며, LOD생물다양성정보통합시스템은 발행된 LOD데이 터의 활용을 위한 예시 사이트로서 구축된 식물, 균류, 척추 동물의 상세설명 및 그와 관련된 연관정보, 검색, 동영상, 음성 서비스 등의 기능을 구현하였다. 대상정보는 기 구축된 국립중앙과학관의 65만개의 데이 터와 국립수목원의 143만개의 데이터 중, 해당 포털에서 인기 검색된 생물종 300종(식물100종, 척추동물100종, 균 류100종)을 선정하여, 생물종 기본 정보 및 각종 연관정보 를 연계할 수 있는 생물다양성정보 DB를 새롭게 구축하였 다. LOD 구축은 대상DB분석 및 구축범위선정, 온톨로지 모 델설계 및 트리플 변환규칙설계, RDF 트리플 변환, 저장 순으로 진행하였고, 연관정보 구축은 정보의 전문성과 정합 성을 위해 분야별 전문가를 선정하여 진행하였다. 또한 LOD활용 측면에서 가장 중요한 인터링킹 구축을 위해 DBpedia, KDATA 등에 있는 관련 LOD 데이터와의 연결 을 통한 매시업 작업을 하였다. 생물다양성 정보의 LOD 구축 효과로는 전문가 중심에서 일반인을 위한 맞춤형 생물다양성 정보를 제공하고, 생물분 야에 대한 다양한 정보를 URI, SPARQL 검색 등으로 손쉽 게 제공함으로서 생물다양성 정보의 접근성 확대와 정보의 활용성을 강화하였다. 또한 스마트폰, 태블릿 PC 등의 스마 트 멀티미디어 교육 환경 조성 및 생물 관련 교육자료 제공등의 효과로 생물다양성 정보의 부가가치 창출이 기대되고 있다. LOD구축의 국내 사례로는 서울시 열린 데이터 광장, 국 립중앙도서관의 국가서지 LOD, 한국사 역사정보 LOD 등 이 있으며, 국외 사례로는 미국의 Data.gov, 영국의 Data.gov.uk, BBC , DBpedia 등이 있다. 하지만, 아직은 LOD로 구축된 국내외 데이터 정보가 빈약하고, 기존의 구 축된 DB를 LOD형태로 변환하는데 비용과 시간이 많이 든다. 또한 LOD변환의 필요성 및 인식이 부족하여, 연관정 보를 임의로 구축하여 연결하는 제한된 형태의 LOD를 구 축하여 제공하는 실정이다. 이에 국가적 차원으로 지속적인 관심과 협조를 통해 기존의 구축된 여러 기관의 데이터를 LOD형태로 변환하여 하나로 통합함으로서 국가지식정보 의 거대 지식베이스 구축에 힘써야 할 것이다.