• Steel and Composite Structures
• /
• 제42권1호
• /
• pp.139-149
• /
• 2022

To simplify the design and reduce the construction cost of traditional multi-girder structural systems, twin I-girder structures are widely used in many countries in recent years. Due to the concern on post-fracture redundancy, however, twin girder bridges are currently classified as fracture critical structures in AASHTO specifications for highway bridges. To investigate the after-fracture behavior of such structures, a composite steel and concrete twin girder specimen was built and an artificial fracture through the web and the bottom flange was created on one main girder. The static loading test was performed to investigate its mechanical performance after a severe fracture occurred on the main girder. Applied load and vertical displacement curves, and the applied load versus strain relationships at key sections were measured. To investigate the load distribution and transfer capacities between two steel girders, the normal strain development on crossbeams was also measured during the loading test. In addition, both shear and normal strains of studs were also measured in the loading test to explore the behavior of shear connectors in such bridges. The functions and structural performance of structural members and possible load transfer paths after main girder fractures in such bridges were also discussed. The test results indicate in this study that a typical twin I-girder can resist a general fracture on one of its two main girders. The presented results can provide references for post-fracture performance and optimization for the design of twin I-girder bridges and similar structures.

• Steel and Composite Structures
• /
• 제51권1호
• /
• pp.9-24
• /
• 2024

In order to study the shear mechanical behavior of prefabricated and assembled multi-key group stud connectors, this paper conducted push-out tests on 10 prefabricated and assembled multi-key group stud connectors, distributed in 5 groups, and detailed the failure modes of each specimen. Based on the finite element software, a total of 22 models of this type of stud connector are established, and validated the finite element models using the push-out tests. Furthermore, the effects of stud diameter, number of key groups, and spacing of key groups on the shear resistance of prefabricated and assembled multi-key group stud connectors are analyzed. Combined with the test and finite element, the force analysis is carried out for the stud and first-pouring and post-pouring concrete. The results show that the spacing and number of key groups have a significant impact on the shear capacity and shear stiffness of the specimen. For a single stud, the shear force is transferred to the surrounding concrete via the stud's root. When the stud is finally cut, the steel and the concrete plate are separated. Under vertical shear force, the top row of studs experiences the highest shear, while the middle row has the least. Based on statistical regression, a formula of assembled multi-key group stud connectors is proposed.

• 한국가금학회지
• /
• 제29권1호
• /
• pp.19-23
• /
• 2002

본 연구의 목적은 산란계 사료내 복합효소제의 첨가가 난각특성 및 영양소 소화율에 미치는 영향을 조사하기 위하여 실시하였다. 사양시험은 47주령 ISA Brown산란계 144수를 공시하였으며, 처리구로는 옥수수-대두박 위주의 사료(CON; 기초사료), 기초사료에 복합효소제를 0.7% 첨가한 구(ME0.1; 기초사료 + 0.1%복합효소제), 기초사료에 복합효소제를 0.2% 첨가한 구(ME0.2; 기초사료 + 0.2% 복합효소제)로 3개 처리로 구성되었다. 총 28일간의 사양시험 기간 동안, 산란을, 난중, 난각강도 그리고 난각두께에 있어서 처리구간에 유의적인 차이는 보이지 않았다. 난황색에 있어서는 복합효소제를 첨가함에 따라 유의적으로 증가하였다. 난황계수에 있어서도 복합효소제의 첨가수준이 증가함에 따라 유의적으로 높아졌다. 건물 소화율에서 처리구간에 유의적인 차이는 없었으나, 질소 소화율에 있어서는 복합효소제의 첨가수준이 증가함에 따라 대조구와 비교하여 유의적으로 높았다. 결론적으로, 산란계 사료내 복합효소제의 첨가가 난황색, 난황계수 그리고 질소 소화율을 향상시키는 것으로 사료된다

• 한국강구조학회 논문집
• /
• 제24권5호
• /
• pp.491-501
• /
• 2012

현재 강재교각 기초부의 설계에 적용되어지고 있는 형식은 기초 콘크리트 내부에 앵커프레임을 설치하여 교각부와 연결하는 형태로 설계 및 시공을 하고 있다. 이는 복잡한 설계와 시공으로 인하여 기초부의 크기가 커지고, 과대 설계되는 경향이 있다. 본 연구에서는 고성능강을 이용한 교각 기초부의 연결상세와 관련하여 새로운 형상을 제안하기 위하여 기존 설계기준에 의한 시험체와 고장력 앵커를 사용한 새로운 연결형상 시험체 등 총 3개의 시험체를 제작하여 실내 시험을 실시하였다. 이를 통하여 각 시험체의 성능을 비교 분석하여 연결형식에 따른 구조물의 거동특성을 분석하였다.

• 한국구조물진단유지관리공학회 논문집
• /
• 제21권2호
• /
• pp.69-77
• /
• 2017

공장생산으로 신속한 시공이 가능한 모듈러 시스템은 하중저항 방식에 따라 보-기둥 프레임식의 개방형 모듈러 시스템과 패널 및 스터드로 이뤄진 폐쇄형 모듈러 시스템으로 구분할 수 있다. 그 중 개방형 모듈러 시스템은 폐쇄형 단면형상으로 모듈간 접합이 어려우며, 특정부분의 하중 집중현상으로 국부좌굴이 발생하여 내력이 저감될 가능성이 있다. 본 연구에서는 기존 모듈러 시스템의 문제점을 해결하기 위하여 절곡형 단면 안에 콘크리트를 채운 합성단면을 사용한 모듈러 시스템을 제안하였다. 제안된 시스템의 내진 성능 평가를 위해 ATC 40의 능력스펙트럼 해석법을 사용하였으며, 일반적인 모듈러시스템의 결과와 비교하여 성능을 검증하였다. 해석결과에 따르면 성능점에서 합성단면을 사용한 모듈러시스템의 소성힌지 갯수 및 변형량이 적게 나타났다. 이를 토대로 제안된 합성단면의 내진성능이 기존 부재 보다 우수 것으로 판단하였다.

• 복식
• /
• 제52권5호
• /
• pp.173-186
• /
• 2002

Street Style, occurred in British and America, has been expressed the character of the new generation by repeating developments and changes. Nowadays, pop music reflects the phase of society. and simultaneously it has influence on from culture to society. Rock Music was rooted in Country 8l western of America. Upon Country & Western, Afro-Americans Rhythm & Blues was added, and that was the birth of Rockabilly. Rockabilly developed to Rock'n 'roll and it started to change to various forms of Rock since 1950s. As the commercial impact and the breakthrough of teenagers emotion, the rock culture comprised the base of the youth culture. However. it formed the anti-establishment culture against the established value, accepting working class subculture. The teenager culture was affected by the Rock culture, also found relief in the opulence provided by the established generation, imitating it as it was. Simultaneously, it had a contrary aspect as anti-establishment form under the banner of revolt against languor in richness. The youth culture created street style that was escaped from high fashion, every time Rock music had changes. Since Street style was based on resistance of established culture and it fully refused vogue, it was indifferent from high fashion. The results of this study were as following. First, every time Rock music had changes, the new youth culture was concomitant with, the youth culture created street style. Secondly, rockahibilly style was characterized as diamond shaped design, embroidery, extra wide shirt collar, vivid contrast color . Rockers style was represented as metal studs, beads, denim, leather jacket, boots. Fusion of hippies style and Psychedelic, long hair, beads. worn denim were elements of headbangers style. Punks style was characterized as ripped T-shirt. rooster hair, over decorated jacket, short skirt. net or plastic T-shirt. Lastly, the firm relation between popular art and fashion was proved by examining the history of Rock Music and Street Style.

• 패션비즈니스
• /
• 제2권1호
• /
• pp.35-48
• /
• 1998

The purpose of this paper is to examine the street fashion, which is influenced by the youth culture in 1960s. Youth culture is the youth subculture which appeared multiform in the 1960s. It tried to create a new culture by subverting the ruling class culture with their combative life style and peculiar appearance which are distinguished from mother culture. Youth cultures as youth subculture are symbolically expressed in their style which had strong characteristics of sub-fashion and anti-fashion, and which are different from mother fashion in shape. Therefore youth subculture fashion had an effect on street fashion in the 60s. The influence that the youth culture fashion had had on the street fashion is summarized as follows: Beats fashion was intelligency look on black dress, black polo-neck shirts, black trousers, black glasses and heavy black eyeliner. Mods fashion was neat style on Edwardian suit with narrow trousers, pointer-toeshoes and smooth croped hair. Folkis fashion was ethnic look, middle east asian look, peasant look, Indian style, south america look, gypsy style, natural materials, natural dying, tie-dye, beads and hand made ornaments. Rockers fashion was violence appearance categorized 'blue collar' on black leather jacket decorated with metal studs and hand-painted insignia, blue jeans and boots for motor bike. Swinging London & the Psychedelics fashion was blend mods look with pschedelic color and motive pattern. Hippie fashion was intermix pschedelic and natural or ethnic style. It was appear to be a meaningless, unpredictable assortment of diverse items and style. Faded and tattered jeans, army jackets, vintage hat, beads, embroidered headband, white sheets, diverse theatrical costumes, sandals or bare feet, granny dress, peasant blouse, blanket cape, tie-dye T-shirts and long hair. Greasers fashion was adorned black leather jacket with chains, fringing, badges, insignia and sleeves had been crudely ripped off. They came to be known wore jeans so soaked with oil. Skinheads fashion was aggressive working class identity with donkey jacket, jeans rolled up, collarless union shirts, heavy boots, braces and hair cropped short.

• 한국산학기술학회논문지
• /
• 제20권11호
• /
• pp.501-509
• /
• 2019

최근 건축과 토목 구조물 기초에 적용되는 말뚝의 시공법은 환경 훼손, 소음 공해, 그리고 주위 민원을 최소화하기 위해 항타공법에서 매입공법 위주로 변화하는 추세를 보이고 있다. 이러한 시공방법의 변화로 인해 기존의 항타공법으로 사용되었던 말뚝 대신, 재료 및 구조적인 시스템 측면에서 보다 최적화되고 경제적인 매입용 말뚝의 개발이 요구되고 있다. 본 연구에서는 매입용 말뚝인 원심성형 철근콘크리트 말뚝의 보강된 이음방법을 제안하였다. 이전의 연구에서는 원심성형 철근콘크리트 말뚝에 대해 연장된 원형띠판과 스터드로 구성된 이음 보강방법이 기존 이음방법의 구조성능을 개선 시킬 수 있을 것으로 검토되었다. 따라서, 본 연구에서는 이러한 이음방법의 구조성능을 말뚝의 휨과 전단 강도 실험을 통해 검증하였다. 이 제안된 이음방법은 설계에서 요구되는 휨과 전단 강도에 대해 충분한 성능을 보인 것으로 실험에서 나타났다. 또한, 전반적인 하중-처짐 거동이 이음부가 없는 일체형 구조에 근접하므로 설계에서 예상하는 거동과 성능이 안정적으로 현장 구조물에 반영될 수 있을 것으로 기대된다.

• 한국안전학회지
• /
• 제33권2호
• /
• pp.86-93
• /
• 2018

Recently, the use of composite steel plate concrete structural modules filled with concrete between steel plates of complex internal structure, in which a large amount of studs are installed, is increasing in order to reduce the weight and to increase workability of structures such as LNG storage tanks. However, in Korea, there is no systematic criterion for evaluating the construction performance of composite steel plate concrete structural modules. Therefore, in this study, we propose a filling guideline of concrete for composite steel plate structural module. For this purpose, high filling performance concrete with general strength range was formulated and tested for filling ability and permeability for each formulation. Rheology analysis was performed to quantitatively evaluate the flow characteristics of concrete. The reliability of $T_{500}$ and plastic viscosity was evaluated to reflect the results of each test, and a guideline for high filling concrete satisfying the reliability of 0.9 or more was derived by reflecting the results of the study on the relationship between the $T_{500}$ and plastic viscosity. Through final fill-box test, filling performance was verified and guidelines were suggested.

• 한국강구조학회 논문집
• /
• 제22권6호
• /
• pp.533-541
• /
• 2010

H형강 보는 기둥 사이에 설치되어 건물의 각 층 바닥인 슬래브를 지지하기 위해 널리 사용되고 있다. 그러나, H형강 보의 경우 접합부가 고정단이면서 등분포하중 작용시 양 단부에 발생하는 휨 모멘트는 중앙부에 발생하는 모멘트에 비해 약 2배가량 크다. 보는 최대 모멘트에 의해 설계가 이루어지기 때문에 보 춤이 커지게 되고, 이로 인하여 각 층의 가용 공간이 줄어드는 문제점이 있다. 이를 개선하기 위해, 최대 휨 모멘트가 발생하는 H형강 보 양 단부만을 별도로 보강하면, 보 중앙부에서 발생하는 휨 모멘트로 보를 설계할 수 있다. 따라서, 단부 보강한 철골보(Eco-girder)의 구조적 성능을 분석하기 위해, 단부 보강 강판의 용도, 철근 보강, 하중전달방법 등을 변수로 하여 4개의 실험체를 제작하여 구조성능실험을 수행하였다.