In this study, we study the behavior of CFT subjected to pure bending moment considering the interface character between the materials. We assume that the interface between the materials has 2 cases, one is full-composite the other is non-composite. Through the analysis of the FEM results, we find that CFT’s flexure behavior is unique compared to other composite structures. There is almost similar CFT’s flexure behavior in the pure moment regardless of interface character between steel and concrete. This is because there is no difference in the neutral axis of the full-composite and non-composite in the CFT scetion.

Wind turbine tower has a very important role in wind turbine system as one of the renewable energy that has been attracting attention worldwide recently. Due to the growth of wind power market, advance and development of offshore wind system and getting huger capacity is inevitable. As a result, the vibration is generated at wind turbine tower by receiving constantly dynamic loads such as wind load and wave load. Among these dynamic loads, the mechanical load caused by the rotation of the blade is able to make relatively periodic load to the wind turbine tower. So natural frequency of the wind turbine tower should be designed to avoid the rotation frequency of the rotor according to the design criteria to avoid resonance. Currently research of the wind turbine tower, the precise research does not be carried out because of simplifying the structure of the other upper and lower. In this study, the effect of blade modeling differences are to be analyzed in natural frequency of wind turbine tower.

The curved bridges shows very complicate behaviors compare to straight girders due to its initial curvature. Usually, the shear strength is investigated due to the aspect ratio(transverse stiffeners spacing/height of girder) and many researches have been conducted for the web shear strength for I-shaped curved girders with high aspect ratios(larger than 3). In this study, numerical studies are carried out and the results are compared with the current design practices. By the analyses, the maximum aspect ratio of a transversely stiffened web panel are suggested to revisits the validity of a limited imposed by Basler.

Compare to straight girders, horizontally curved girder shows complicate behaviors because the bending moments and torsional moments are always acting simultaneously. Because of non-uniform torsion, one edge of compression flange is yielded faster than the other edge due to combined vertical and lateral moments. Hence, the strength of cross section need to be investigated with the effect of initial curvature. The design specifications, however, does not consider the curvature effect. In this study, as a basic research, the parametric studies are performed to understand the flange local buckling behaviors of horizontally curved girders.

Natural frequency characteristic of Wind turbine tower is important for designing of tower due to guarantee of structural safety of tower. In GL specification, natural frequency of tower should be designed by consideration of blade rotational frequency. Natural frequency characteristic of tower could be changed by mass ratio of RNA-tower, modeling method of blade and angle of blade in idling condition. In this research, natural frequency of tower is analysed by ABAQUS and compared it result according to tower dimension.

It is same such as the provision of shear buckling strength of steel composite box girder web panel and plate girder web panel in Korea Highway Bridge Design Standards(2012). But the web panel of steel composite box girder is different from the web of plate girder in that the upper slab and lower flange are connected to the web. So a different shear behavior of the girders is expected. In this study, To calculate a reasonable elastic shear buckling strength of steel composite box girder web panel, ABAQUS program was used. The results from F.E.A and previous studies are compared.

It is same such as the provision of shear buckling strength of steel composite box girder web panel and plate girder web panel in Korea Highway Bridge Design Standards(2012). But the web panel of steel composite box girder is different from the web of plate girder in that the upper slab and lower flange are connected to the web. So a different shear behavior of the girders is expected. In this study, To calculate a reasonable elastic shear buckling strength of steel composite box girder web panel, ABAQUS program was used. The results from F.E.A and previous studies are compared. It is shown that the web shear buckling strength of steel composite box girder of Korea Highway Bridge Design Standards(2012) is the most conservative.

In this study, uniaxial compression tests were performed to investigates the stress-strain relations of Double Skinned Composite Tubular Columns reinforced with steel tube. The confined concrete has been known as the strength of concrete increases significantly. Specimens reinforced with outer and inner steel tube were tested by uniaxial compression test. To investigate the influence of concrete strength increase by confining conditions in steel tubes, 8 specimens with different thickness of tube, hollowness ratio and concrete strength were tested and compared with other researcher's concrete material model.

오랜만에 느낀 긴 추석연휴의 달콤함도 끝났습니다. 각각의 계절마다 고유한 냄새가 있습니다. 그것이 진정 후각적 냄새인지 아니면 몸의 느낌으로 감지하는 심경변화인지는 잘 모르겠지만, 선선한 바람이 부는 아침이나 저녁이면 확실히 가을 냄새가 나곤 합니다. 여러 가지 어려움을 딛고 2009년 학회가 출범한 이래 우리학회는 아직 겨울을 벗어나지 못하고 있다고 느낄 수도, 새싹이 돋아나는 봄이라고 느낄 수도 있을 것입니다. 그러나 현재 우리나라 건설시장은 혹독한 겨울과 같이 녹록치 않다는 것은 모든 회원분들이 공감하실 거라 생각합니다. 가장 근본적인 것은 건설산업이 나아가야 할지향점이 구조적으로 변화하고 있다는 점입니다. 지금까지 안전성(Safety)과 경제성(Economic)만을 강조한 성장위주의 페러다임 이였다면 이제는 사용성(Serviceability), 심미성(Esthetic) 그리고 환경(Environment)을 고려한 창조적이고 획기적인 건설산업을 생각해야 될 시기입니다. 이러한 면에서 저희 한국복합신소재구조학회의 설립취지나 시기가 매우 적절하다고 판단됩니다. 안전성과 경제성을 확보하면서 사용성과 심미성을 갖추기 위해서는 기존에 많이 사용되는 콘크리트와 강재의 장점을 이용한 간단하면서도 획기적인 복합구조체의 개발과 더 나아가 새로운 소재를 사용한 구조물의 정확한 거동을 분석하고 설계할 수 있는 기술이 반드시 구축되어야 할 것입니다. 이를 바탕으로 최근 이슈가 되고 있는 소음 및 진동에 관한 문제뿐만 아니라 기존 구조물 보다 날렵하고 아름다우면서 안전한 구조물의 설계 및 시공이 가능 할 것입니다. 또한 환경적인 측면을 살펴보면 우리나라는 OECD국가중 이산화탄소 발생량 증가율이 가장 높고, 분야별 1인당 배출량은 제조⋅건설분야에서 OECD의 평균을 웃돌고 있습니다. 2020년 우리나라 온실가스 감축 목표치가 배출전망치(BAU)대비 30%(2005년 대비 4% 감축)를 줄이는 것으로 계획하고 있습니다. 현재까지 건설재료로서 가장 많이 사용되는 콘크리트와 강재의 경우 콘크리트(시멘트) 1ton을 생산하는데 발생하는 이산화탄소는 약 1.3T-CO2이고, 철강재 1ton을 생산하는데 발생하는 이산화탄소는 약 2.1T-CO2입니다. 이러한 상황에 복합신소재의 사용은 부재 단면의 축소뿐만 아니라 콘크리트와 강재의 사용량을 줄여 이산화탄소 발생량의 감소를 통한 친환경적인 건설시장을 주도 할 수 있을 것입니다. 이러한 우리학회의 좋은 설립취지, 목적, 그리고 소수인원의 노력만으로는 학회의 발전을 기대하기는 어렵습니다. 많은 회원분들의 적극적인 참여와 활동이 필수적이며 저 또한 회원 여러분의 참여와 학회의 발전을 촉진시키기 위해 심혈을 기울이겠습니다.

This study investigates the stress-strain relations of internally confined hollow concrete filled tube pier reinforced with GFRP tube by uniaxial compression test. The confined concrete subjected multi-axial stresses have been known as the strength of concrete increases significantly. Many researchers have studied in confining effects of CFT which have only outer GFRP tube. In this study, specimens reinforced with outer and inner GFRP tube were tested by uniaxial compression test. To investigate the influence of concrete strength increase by confining conditions in GFRP tube, 13 specimens with different thickness of tube, hollowness ratio and nominal concrete strength were tested and compared with Steel tube.

This study investigates web shear buckling behavior of composite box girder according to the aspect ratio. The nonlinear finite element analyses on composite box girder model having shell elements and solid elements were performed. Also, the steel was modeled as an elasto-plastic material. Ultimate web shear buckling behavior of composite box girder was analyzed, and were compared the inelastic analysis results with shear buckling behavior of plate.

Concrete and steel has been used as the main material of structure from building and drainage pipe. However, many problems such as corrosion and rupture had occurred in the Water Supply and the Sewer System. Additionally, the government has invested big budget to Deteriorated pipe replacement and maintenance. Replacement of existing pipelines in order to solve these problems, GFRP pipe(glass fiber composite material pipes) is aspiring to replace the tube. GFRP has high strength, restore performance, durable and lightweight properties. However, high strength GFRP pipe is weak in buckling problem. This study is to analysis Optimization Design models for resisting bucking problem of GFRP pipes. Thus, various tests Changed the angle of Glass-Fiber-Reinforced Layer and the resin content of resin-mortar were performed for GFRP pipes to estimate material characteristics of GFRP in this study. Buckling analysis of composite structures under external uniform pressure was performed with the results obtained through test.

This project investigated the use of two types of thermoplastic pipes, High-Density Polyethylene (HDPE) and Poly-vinyl Chloride (PVC), as cross-drains under highways. Pipes ranging from 0.3 m (12 in.) to 1.5 m (60 in.) in diameter were evaluated under deep fills, minimum cover, and construction loads. In addition to a comprehensive literature review, an analytical study into the allowable fill heights for thermoplastic pipes and a field study to observe the installation and performance of the pipe in service conditions were conducted. Based on the study findings, recommendations regarding how and when thermoplastic pipe should be installed are provided.

Recently, there is to increase interest in seismic performance of piers. Hollow section is applied to increasing the seismic performance of piers. However, hollow RC pier becomes the biaixial confining state because hollow part is not confined. The pier is developed brittle failure from inner face in hollow part. A tube is inserted in hollow part to become the weakness. This is ICH RC(Internally Confined Hollow RC) pier. This pier is enhanced stiffness, strength, and ductility by core concrete has triaxial confining stress. In this paper is researched about parameters effect the seismic performance. Parameters are hollow ratio, transverse reinforcement, longitudinal reinforcement, and concrete strength.

Recently study of confining effect in column member is progressed. But these studies are limited to about RC column and external confining effect in hollow column. Internal confining effect in hollow column has not researched that generally assumed the same external confining effect. In this study there are to investigate the internal direction confining effect ICH RC columns. We performed parametric studies to find main parameters that affect the internal confining effect. Parametric study has performed using FEA program (ABAQUS) which parameters are hollow ratio, diameter of column.

This study investigates the elastic behavior characteristics of GRP pipes reinforced with trapezoidal ribs instead of rectangular ribs. Han(2006) proposed GRP pipe reinforced with rectangular ribs in 2006, to promote buckling strength of the pipe. But it is more difficult to reinforce pipe with rectangular ribs than external corrugated ribs, because of pipe manufacturing process referred to as filament winding. Therefore, This study investigated the elastic behavior characteristics of the GRP pipe reinforced with trapezoidal ribs for simplifying analysis approach of external corrugated ribs.

본 연구는 등분포 하중에 종속된 폼내장 콘크리트 샌드위치 패널 (foam insulated concrete sandwich panel)의 구조거 동특성을 파악하였다. 유한요소모델이 콘크리트, 폼 그리고 철근의 비선형거동과 연결부재 (connector)의 상세 전단 저항거동을 모사하기위해 사용되었다. 개발된 모델은 미주리대학 (University of Missouri)에서 수행된 정적실험자료 를 사용하여 검증되었다. 합성 및 비합성 거동이 샌드위치패널의 구조거동에미치는 영향을 정확히 모사하기 위해 전단연결재의 저항력을 모델에 정확히 반영하는 것이 중요하다. 본 연구에서 개발된 모델은 구조물의 극한강도및 좌굴이후의 거동까지 모사하였고 미국콘크리트 학회 (ACI)의 설계예제와 비교하였다. 본연구의 결과는 정적 및 동 적하중에 종속된 폼내장 콘크리트 샌드위치 패널의 해석및 설계에 유용한 정보를 제공할것이다.