최근 프리팹 부재간 비간섭 계면이음 설계기술이 도입되고 기계주입식 충진 기술의 실용화 성공으 로, 교량 프리캐스트 바닥판 시공의 저해요인이 상당히 해결될 수 있다. 이 때 프리팹 부재에 GFRP 보강근을 적용한다면 가공조립비 절감 효과가 있고, 프리팹 부재의 경량화로 경제성이 제고될 뿐 만 아니라, 현장 안전성과 작업편의성이 향상될 것으로 보인다. 기존 철근 연신율은 20% 내외 수준인데 반해 GFRP 보강근의 파괴변형율은 3% 내외이며 탄성계수는 50GPa (강재 대비 25%수준)이므로, 이 러한 재료특성 차이로 인한 휨성능에 대한 영향 평가가 필요하다. 특히 GFRP 보강근을 프리캐스트 바닥판과 거더 간 계면이음 적용에 따른 영향을 평가하기 위한 프로토타입 거더를 설계하고, 재료간 계면의 부착 특성을 고려한 유한요소해석 모델을 수립하고 극한 휨성능과 소요 계면 전단성능과의 상 관관계를 검토하였다. 추후 본 변수해석 연구에 대해 실험적 검증이 완수된다면, GFRP 보강근 설계기 술을 정립하는 데 기여할 것으로 기대된다.
The purpose of this paper is to improve the inappropriate analysis results when the end of the brace on braced frame is applied as pinned connection in practice. The stiffness of the gusset plate connection on the braced frame has the amount of between pinned and rigid connection, and the analysis model that applies the stiffness of the connection must be used for accurate performance evaluation. In this study, the stiffness of the gusset plate designed by the balanced design procedure are quantified, and applied to the analysis model to simulate the gusset plate connection. The proposed model was verified through nonlinear static analysis (pushover analysis) of SAP2000. The effect of the connection on the seismic performance of the braced frame was analyzed by comparing the proposed model and pinned model. As a result, it was confirmed that the performance of the braced frame was evaluated conservatively in practice, and the ductility was overestimated. Therefore, it is important to consider the connection for accurate and economical performance evaluation.
This paper examines the seismic performance and structural design of the ceiling bracket-type modular connection. The bracket-type system reduces the cross-sectional area loss of members and combines units using fitting steel plate, and it has been developed to be fit for medium-story and higher-story buildings. In particular, this study conducted the cyclic loading test for the performance of the C-type and L-type brackets, and compared the results. The test results were also compared with the commercial FEA program. In addition, the structural design process for the bracket-type modular connection was presented. The two connections, proposed as a result of the test results, were all found to secure the seismic performance level of the special moment steel frame. In the case of initial stiffness, the L-type bracket connection was found to be great, but in the case of the maximum moment or fully plastic moment, it was different depending on the loading direction.
ACT Column은 기존 CFT 기둥보다 얇은 강판으로도 동일한 구조적 성능을 발휘할 수 있으며, 콘크리트의 구속효과와 강관의 항복 후 좌굴응력의 향상을 기대할 수 있다. ACT Column은 보-기둥 접합부에 외다이아프램을 사용한 접합상세가 적용된다. 그러나 ACT Column 외부에 콘크리트가 피복되는 SRC 타입에서는 외다이아프램을 사용한 접합부의 적용이 난해하다. 그래서 ACT Column의 외부에 수직 스티프너와 수평 스티프너를 사용한 접합상세를 제안하였다. 본 논문에서는 제안상세를 대상으로 단순인장실험을 통해 성능검증을 수행하였다. 실험체는 현장에 사용량이 많은 크기의 ACT Column 으로 2개의 실험체를 제작하였다. 보 플랜지와 보 플랜지의 양측부에 부착된 윙플레이트를 통해 보 플랜지의 단면 내력이 링다이아프램으로 전달되는 명확한 응력전달매커니즘을 나타내었으며, 보 플랜지 전단면이 소성화되어 파괴되었다. 윙플레이트의 크기가 클수록 하중전달량이 증가하였으며, 제안한 접합상세의 강도평가식을 제시하였다.
In this study, we conducted a shake table test to verify the seismic performance of the paneling system with steel truss composed of bolt connections. The control group was set to the traditional paneling system with steel truss connected by spot welding method. Test results showed that the bolted connection type paneling system has excellent deformation capacity without cracking or brittle fracture of the steel truss connection parts compared to the welding type paneling system. Furthermore, in the bolted connection type, slight damage occurred at the time of occurrence of the same story drift angle as compared with the existing method, it is considered that it has excellent seismic performance. In compliance with the performance-based design recommended for the current code (ASCE 41-13) on non-structural components, it is judged that in the case of the bolted connection type paneling system, it can be applied to all risk category structures without restriction. However, in the case of traditional paneling system with spot welding method, it is considered that it can be applied limitedly.
Two types of connection between the abutment and CFT pile were proposed for the sub-structure of the integral abutment bridge. One was a bolt connection (Type-A) and the other was a hook connection (Type-B). To analyze the performance of connection Type-A and Type-B, a quasi-static experiment was carried out. According to experimental results, the destruction occurred at the connection point and so both type A and type B need to have a reinforced design as the link between the abutment and CFT pile. However, when the load resistance performance and energy dissipation capacity was analyzed, the performance of connection Type-B was superior to the performance of connection Type-A.
In this study, a quasi-static experiment was conducted on the connection performance between the integral abutment bridge and CFT pile. Six experiment specimen were manufactured and were divided into type A and type B. Experiment specimens of Type A were connected with bolts and experiment specimens of Type B were connected with hooks. In the experiment results the connection performance of Type B showed excellent performance more than that of Type A.
In this study the structural performance of new composite column to composite beam connection was evaluated by cyclic tests. It is designed to be applied to various types of through type system to the bottom plate to view synthesis composite beam. A composite column is composed of a RC type column reinforced by steel angles which the end bends in each edge corners of column. also, A composite beam is composed of trussed type’s web, a bottom steel plate and reinforced by steel angles which the end bends in each edge corners of beam. 4 cyclic tests of the clarified structural performance of the connections are performed. All specimens that is apply reinforced concrete beam-column joints based on KBC2009 criteria was performed by cyclic test of column to beam. All specimens were exposed to be satisfied with the required ultimate strength.
To overcome the weakness of spread foundation in large space structure, the research of precast pile for replace spread foundation have been conducted. The new type of joint between PHC pile and steel column is named HAT Joint(Hollow hAlf-sphere cast-sTeel Joint). It connected PHC Pile by bolt that verification of bolt connection should be accomplished. In this paper, pull-out test and flexural performance for HAT Joint to verifying the bolt connection is explained. As a result, the pull-out and flexural capacities of bolt were checked to use in real structure. Furthermore, the equation of pull-out strength was proposed.
Main topics in this study is a new structural detail for connection between H-Steel or SRC column and flat plate slab. We carried out to evaluate the punching shear performance of H-steel or SRC column + RC slab system for vertical load and lateral load. From the test results structural characteristics - yield moment, yield rotation, maximum moment, deformation capabilities ect. - are obtained and evaluated. In this paper as a shear reinforcement for supporting region of plate closed stirrup type and shear band are used, and their test results are compared.
This study investigates the difference between popular genre of mobile games and that of online games, and also the impact of affiliation with social network platform on the market performance. The results show that three genres such as action, puzzle, and RPG occupy a higher market share than the other genres. The structure of the mobile game market is more competitive than that of the online game market but game applications developed by top four developers - CJ E&M, NHN, com2us, WeMade - have been holding high ranks for months. It implies that the structure of the mobile game market is gradually becoming more concentrated. As the market competition increases, the marketing cost for acquiring recognition and the commission fee paying for platform have been increasing accordingly. Consequently, mobile game developers are encouraged to enhance the quality of their games as well as to devise diverse platform-marketing strategies in order to accomplish stable market performance.
In recent years, the construction of high-rise buildings are promoted. According to these, there are many needs about new technologies to strengthen the building performance and high-strength steel is regarded as one of these for promoting building performance. In Korea, high-strength steels which stress are over 600MPa are on market and in aborad, super high-strength steels over 1000MPa are developing and they expected to promote the building performance. But there are still doubts about applying high-strength steel members because of size effect and worry of brittle fracture. In this reports, we propose results of performance and analysis tests for use with general steel. We propose the characteristic of high-strength steels first and next the results of performance test to show they satisfy the performance that designers expect. And last, we compare the results of test and analysis for acquire the alanysis reliability in non-linear analysis with high-strength steels.
최근 진행되고 있는 건축 프로젝트는 기존의 정형적인 구조계획에서 벗어나 점차 복합적이고 다양한 형태를 지향하고 있다. 이와 같은 새로운 건축 트렌드 속에서, 비정형 건축물의 구조 시스템을 효율적으로 현실화하여 골조의 직교성을 해체시키는 기술에 대한 연구의 필요성이 대두되고 있다. 비정형 건축물의 중요한 구조적 특징 중 하나로 경사기둥의 빈번한 적용을 들 수 있다. 경사기둥은 접합된 보에 추가적으로 모멘트와 축력을 전달하므로, 이러한 현상이 골조 및 보-기둥 접합부의 거동에 어떠한 영향을 미치는지를 실험 혹은 해석을 통해 검증할 필요가 있다. 그러나 수직기둥-보 접합부에 비하면 경사기둥-보 접합부에 대한 연구는 현재까지 충분한 연구가 이루어지지 않고 있는 실정이다. 따라서 본 연구에서는 비선형해석 및 유한요소해석을 사용하여 경사기둥을 포함한 보-기둥 접합부의 성능을 평가하였다. 경사기둥을 포함한 철골모멘트 골조의 비선형정적해석을 통하여 골조 전체의 거동을 분석하였고, 경사기둥-보 접합부 모델의 유한요소해석을 통해 좌굴거동 및 취성파단 잠재성을 검토하였다.
The government supports politic funds to Small Business having difficulties of insufficient capital and weak assets. Also the effect of governmental politic funds are evaluated better than the effect of substitute loans of the commercial bank. Especially
본 연구는 8개의 RBS(reduced beam section) 내진 철골모멘트접합부의 실물대 실험결과를 요약한 것이다. 실험의 주요변수는 보 웨브 접합법 및 패널존 강도를 택하였다. 균형 패널존 시험체는 접합부의 내진성능을 감소시키지 않으면서, 보와 패널존이 함께 균형적으로 지진에너지를 소산시키도록 설계하여 값비싼 패널존 보강판(doubler plates)의 수요를 줄이고자 시도한 것이다. 보 웨브를 용접한 시험제는 모두 특별 연성모멘트골조에서 요구되는 접합부 회전능력을 충분히 발휘하였다. 반면 보 웨브를 볼트 접합한 시험체는 조기에 스캘럽을 가로지르는 취성파단이 발생하는 열등한 성능을 보였다. 보 그루브 용접부 자체의 취성파괴가 본 연구에서와 같이 양질의 용접에 의해 방지되면, 스켈럽 부근의 취성파단이 다음에 해결해야 할 문제로 대두되는 경향을 보인다. 보 웨브를 볼팅한 경우에 접합부 취성파단의 빈도가 월등히 높은 이유를 실험 및 해석결과를 토대로 제시하였다. 측정된 변형도 데이터에 의할 때, 접합부의 전단력 전달메카니즘은 흔히 가정하는 고전 휨이론에 의한 예측과 전혀 다르다. 이는 전통적 보 웨브 설계법을 재검토할 필요가 있음을 시사하는 것이다. 아울러, 접합부에서 요구되는 바람직한 거동기준을 제시하고 이를 근거로 균형 패널존의 강도범위에 대한 예비적 추정치를 제시하였다
다양한 리모델링 시공 중 추가적인 하중저항을 확보하기 위한 기초시공에서는 경제성, 시공성, 소음/진동 등의 이유로 헬리컬 파일을 사용하고 있으며, 좁은 공간에서 소규모 장비를 사용하여 회전관입하므로 파일의 길이가 3m로 제한되어 다수의 연결부가 소요된다. 이러한 연결을 위해 주로 가격이 낮은 pin 타입의 연결부가 사용되고 있으나 토크에 대한 저항력이 낮고 그라우팅이 어려운 단점을 가지고 있다. 이에 기존 대비 20% 이상 토크저항성을 가지며 동시에 경제성을 확보할 수 있는 새로운 헬리컬 파일 연결부를 고안하였고 유한요소해석을 통해 구조성능을 분석하였다.
In this paper, seismic performance evaluation using 3D modeling of structural analysis was carried out to confirm and enhance the seismic performance of modular houses through the seismic performance evaluation scheme. Based on the results, the performance of structural members and joints in the modular house was investigated.
This paper was conducted to evaluate structural performance of modular system connection with bracket. It was evaluated to two external connection specimens and two internal connection specimens. As a result of experiment, excessive shear deformation of the bracket was observed in all of the specimens. However, all of the specimens satisfied the requirement for intermediate moment frames (IMF) targeted in the experiment.
The purpose of this study was to experimentally evaluate seismic performance of connection of modular system. As a result of experiment study, two specimens did not show the strength reduction and brittle fracture at connection until 2% story drift. Thus, requirements for intermediate moment frame(IMF) was satisfied in two specimens.