강바닥판 종리브와 횡리브 교차부의 피로거동에 대한 종리브내 다이아프램의 영향

최동호,최항용,최준혁,Choi, Dong Ho,Choi, Hang Yong,Choi, Jun Hyeok 한국강구조학회 2000 韓國鋼構造學會 論文集 Vol.12 No.3

본 연구에서는 강바닥판의 실물 대형시험체를 제작하여 정적시험 및 피로시험을 실시하였다. 정적 및 영향면 재하시험 결과를 통하여 다이아프램의 유무에 따른 강바닥판 슬릿부의 면내와 면외응력을 검토하였으며, 피로시험결과로부터는 강바닥판의 피로거동, 피로균열의 발생과 진전에 대한 연구를 수행하였다. 다이아프램이 설치된 상세는 설치되지 않은 상세에 비하여 지점조건에 상관없이, 종리브 횡리브 교착부의 종리브측으로는 약 50%의 응력경감효과가 있으나, 횡리브측 하단부에는 오히려 상당히 큰 응력을 야기함을 알 수 있었으며, 피로균열 진전해석결과로부터는 슬릿부의 노치에 의한 초기균열길이가 피로균열성장에 상당한 영향을 끼치고 있음을 알 수 있었다. 측정자료와 FEM 해석을 통하여 공칭응력과 핫스폿응력에 의한 피로강도를 추정한 결과, 다이아프램이 설치되지 않은 상세는 규정된 피로등급에서 안전한 것으로 판단되나 다이아프램이 설치된 상세는 피로등급이하의 거동을 보였다. This study investigates the mechanical behavior on trough rib to crossbeam joint in orthotropic steel plate decks, specially emphasizing on the effect of diaphragm inside trough rib on the fatigue behavior of slit by static and fatigue tests. In particular, the effects of diaphragm on in-plane stress and out-of-plane stress, stress concentration, propagation of fatigue cracks at the silt are studied. With the result of experiment and numerical analysis, we have estimated the fatigue strength using the nominal stress and hot-sport stress. The details with diaphragm have occurred about 50% stress reduction at trough rib part of trough rib to crossbeam joint than the detail without diaphragm, however, the lower parts of crossbeam have occurred much more stress. Initial crack size or slit have an considerable influence on the propagation of fatigue cracks due to V-notch. The fatigue strength category of the details without diaphragm has higher value than fatigue limit, whereas that of the details with diaphragm is estimated lower than fatigue limit.

일축압축을 받는 직교로 보강된 판의 좌굴강도

최동호,장동일,최항용,Choi, Dong Ho,Chang, Dong Il,Choi, Hang Yong 한국강구조학회 1998 韓國鋼構造學會 論文集 Vol.10 No.4

직교로 보강된 판은 효율적인 하중분배능력과 좌굴안정성 때문에 장대교량의 강상판으로 사용되고 있다. 본 연구에서는 일축압축을 받는 직교로 보강된 판의 좌굴강도를 해석적 방법으로 추정하였다. 판이론을 사용하여 전체좌굴 및 부분좌굴과 같은 여러 모드에서의 좌굴응력식을 유도하고, 좌굴강도에 대한 횡리브와 종리브의 강성과 개수 등의 효과를 보이기 위하여 매개변수해석을 수행하였다. 정량적인 해석을 통해 종리브와 횡리브의 강성과 간격의 영향을 보였다. Orthogonally stiffened steel plates are used for orthotropic steel decks of long-span bridges because of high degree of flexural and torsional resistances and good load-distribution behavior. An analytic study is presented for evaluating the buckling strength of orthogonally stiffened plates subjected to uniaxial compression. By using the plate theory, the buckling stress under overall and partial buckling modes, is derived. Parametric studies are performed to show the effects of the stiffness and the number of transverse and longitudinal ribs on the buckling strength. The results show quantitatively strong influence of stiffness and spacing of longitudinal and transverse ribs.

백석 문학의 전체성에 대하여

최동호(Choi, Dong?ho) 한국비평문학회 2012 批評文學 Vol.- No.46

This paper aims to have a bird’s?eye view on Baek, Seok’s works who has reached the 100th anniversary and avoid the mistake of looking into the parts and not the whole. Paek, Seok was born at Jeong?ju, Pyeong?buk on July 1912 and lived a life of extreme ups and downs. He made his literary debut through annual spring literary contest of Chosun Daily newspaper on January 1930 when he was 19 and finished his publication of works with ‘Naruteo’(Ferry) on May 1962. After he went to a cooperative in Gwanpyong?ri, Samsoo?gun leaving the central literary circle on January 1959, he lived as a shepherd for more than 30 years of his later part of life. Having been brought into sudden prominence in the literary circle with his poem book Saseum(Deer) in 1936, Paek, Seok kept his literary reputation as a writer of juvenile stories by publishing fairy poem book Jipgene Ne Hyongje(Four Brothers of the Hermit Crabs, 1957) in the North Korea. However, he had to focus on children’s literature without the freedom of writing and he could not be reinstated to Pyongyang after he had received the ‘Red Letter’ in 1959. Referred as a genius poet, however, his life was ended tragically without beingable to write what he wanted to and criticized for his lack of loyalty and ‘vestige of bourgeois.’ Total unearthed poems of Paek, Seok are 148 including recent ones discovered by Song, Joon. More of his unearthed works will be included later. His proses are total 44 with the variety of novel, essay, review, political comment, translation, etc. He focused more on translation in the North Korea and they are 197 works of translated modern poems and 11 works of fairy poems. He translated 4 long novels including Silent Don 1, Silent Don 2 and 1 collected short novel and 2 short novels. Silent Don recently discovered with the help of professor Yoon, Hae?yeon is more than 1,000 pages and has an importance as the first direct translation fro Russian into Korean by Bake, Seok. More works of him will be unearthed as time goes on. However, with those newly unearthed works, the study on Baek, Seok’s literature has already reached a new phase. Now researchers have to include those works written in the North Korea. Unearthing the texts of important poets such as Baek, Seok is very meaningful for the study of modern Korean poetry. Considering the process of unearthing his works until now, more of his translated works will be found. However, his own creation has less possibility of being included in the list. Though there will be the difficulties such as the division of Korea into south and north, researchers should be able to get over them to continue the study of Baek, Seok.

단면감소를 고려한 파이프의 좌굴에 관한 연구

최동호,고영찬,권순길,이종선,Choi, Dong-Ho,Ko, Young-Chan,Gwon, Sun-Gil,Lee, Joung-Sun 대한토목학회 2013 대한토목학회논문집 Vol.33 No.3

본 연구에서는 부식이나 보강재가 고려된 비균일한 두께를 가지는 파이프라인에 대하여 일정한 외압을 받을 때의 탄성 좌굴하중을 이론적으로 산정하였다. 길이가 매우 긴 원통형 쉘 구조물인 파이프라인을 단순한 링 구조물로 가정하였고, 고유함수를 유도하여 좌굴 임계하중을 산정하였다. 또한, 두께 변화와 두께가 감소된 구간의 범위에 따른 변수해석을 수행하였다. 이론식에 의해 산정된 좌굴 임계하중 결과를 유한요소해석 결과와 비교하여 검증하였고, 두 결과는 잘 일치함을 알 수 있었다. This paper proposes a theoretical solution of elastic critical buckling load of infinitely long pipelines with non-uniform thickness under external pressure. The non-uniform cross section of pipelines can be considered as corroded or stiffened pipelines so that this paper can be a fundamental research of pipelines that are essential technology for offshore industries. The theoretical solution of pipelines with non-uniform thickness is derived with an assumption that a cylindrical shell under external pressure can be considered as a simple ring. The eigenfunctions are derived to obtain the critical buckling load. The reduced thickness and the reduced range are considered as variables in parametric analysis. The finite element analysis is performed to verify the theoretical solutions and the results of the analytic method and the finite element method are in good agreement.

건축물 방화문 성능기준 개선방향에 관한 연구

최동호,서희원,Choi,Dong Ho,Seo,Hee Won 한국방재학회 2013 한국방재학회논문집 Vol.13 No.1

화재시 건물내의 연소확대를 방지하기 위한 방화구획 선상 및 피난통로 등에는 방화문, 방화셔터 등을 설치하기 위한 개구부가 위치하게 된다. 건축물에서의 연소확대는 이와 같은 개구부를 통하여 이루어지기 쉬우므로 설치되는 방화문 등 개구부 방호설비에 대한 관련 기준의 정비 및 보완이 중요하다. 현재 국내에서는 방화문의 경우 설치부위의 내화성능 등에 관계없이 비차열 1시간 성능만을 적용토록 하고 있어 화재 발생시에 충분한 연소확대방지를 기대하기 어려운 실정이다. 이에 본 연구에서는 외국의 방화문 성능기준을 검토하여 국내 방화문의 성능기준을 개선하기 위한 기초자료를 제시하고자 하였다. The openings for fire doors and fire shutters are installed on fire compartment to stem fire spreading and evacuation passage in building. Fire spreading tend to grow through these openings, so it is important to organize the standard related to opening protectives. In case of the fire door in Korea, its criteria is only integrity 1 hour regardless of fire resistance of a building member, therefore it is difficult to protect the fire spreading effectively. In this study, foreign performance criterion of the fire door were reviewed and the base data for improving way about the fire door performance criteria were suggested.

단자유도 시스템의 선형응답과 비탄성응답에 미치는 PSD함수의 영향

최동호,이상훈,김용식,고정훈,Choi,Dong-Ho,Lee,Sang-Hoon,Kim,Yong-Sik,Koh,Jung-Hoon 한국방재학회 2008 한국방재학회 학술발표대회논문집 Vol.2008 No.1

Acceleration time history (ATH) used in the seismic analysis should envelop a target power spectral density (PSD) function in addition to the design response spectrum in order to have sufficient energy at each frequency for the purpose of ensuring adequate load. Even though design regulations require the ATH used in seismic analysis to meet a target PSD function, the reason that ATHs meet to a target PSD function is not described. Thus, artificial ATHs for high PSD function and artificial ATHs for low PSD function are generated. And then elastic and inelastic single-degree-of-freedom (SDOF) systems are loaded with these artificial time histories as the earthquake load. As a result, linear response and inelastic response of SDOF systems are affected by PSD function.

100작품 - 개념의 건축화된 4카테고리 스케치 (우주.내용과 형식. 미메시스. 별자리)

최동호,Choi, Dong-Ho 대한건축사협회 2012 建築士 Vol.2012 No.2

장대레일 궤도의 온도좌굴 거동에 미치는 열차하중의 영향

최동호,김호배,Choi, Dong Ho,Kim, Ho Bae 한국강구조학회 2000 韓國鋼構造學會 論文集 Vol.12 No.6

The present study investigates the influences of vehicle induced loads on the thermal buckling behavior of straight and curved continuous welded rail (CWR) tracks. Quasi-static loads model is assumed to determine the uplift region, which occurs due to the vertical track deflection induced by wheel loads of vehicle. The lateral loads of vehicle induced by weight, the speed, the superelevation and curvature of track, and other dynamic vehicle track interaction, are included in the ratio of lateral to vertical vehicle load. Parametric numerical analyses are perfomed to calculate the upper and lower critical buckling temperatures of CWR tracks, and the comparison between the results of this work and the previous results without vehicle is also included. 본 연구에서는 궤도의 좌굴해석 및 그 결과를 통해 열차하중이 직선 및 곡선 장대레일 궤도의 온도좌굴 거동에 미치는 영향에 대해 평가하였다. 차량을 고려한 온도좌굴 해석은 바퀴하중하에서 장대레일 궤도의 수직 처짐에 기인한 상향처짐을 결정하기 위해 유사정적 하중모델을 가정하였으며, 차량의 무게와 속도, 궤도의 곡률, 캔트, 그외의 열차와 궤도의 동적인 상호작용으로 인한 횡방향하중은 열차의 수직하중에 대한 수평하중 비에 포함하여 수행하였다. 수치적 해석을 통해 장대레일의 상부 및 하부좌굴온도를 구하였고, 이런 해석결과들을 기존의 열차하중을 포함하지 않은 정적 좌굴해석결과들과 비교하였다.

승강기문, 방화유리창 성능기준 개선방향에 관한 연구

최동호,김대회,서희원,박수영,Choi. Dong Ho,Kim. Dae Hoi,Seo. Hee Won,Park. Soo Young 한국방재학회 2013 한국방재학회논문집 Vol.13 No.1

화재시 건물내의 연소확대를 방지하기 위한 방화구획 선상, 피난통로, 승강기 탑승 로비 등에는 방화문, 승강기 등을 설치하기 위한 개구부가 위치하게 된다. 건축물에서의 연소확대는 이와 같은 개구부를 통하여 이루어지기 쉬우므로 설치되는 개구부 방호 설비에 대한 관련 기준의 정비 및 보완이 중요하다. 특히 과거와는 달리 건물의 고층화, 대형화에 따라 피난용도로 사용되는 승강기의 용도가 중요시 되고 있으며, 이에 따른 승강기문에 대한 화재안전성이 요구되고 있으며, 또한 방화문 등에 설치되는 방화유리창도 화재시 연소확대방지를 위한 검토가 필요하다. 이에 본 연구에서는 외국의 방화용 승강기문과 방화유리창에 대한 성능기준을 검토하여 국내 관련 성능기준을 설정하기 위한 기초자료를 제시하고자 하였다. The openings for fire doors and elevator doors are installed on fire compartment to stem fire spreading, evacuation passage and elevator hoistway in building. Fire spreading tend to grow through these openings, so it is important to organize the standard related to opening protectives. Unlike in the past, due to being tall and large, the elevator for evacuation is being more important. For this reason, it is required for elevator door to be safe in fire and it is necessary for the glazing installed on fire doors to be reviewed with respect to fire spreading. In this study, foreign performance criterion of the fire elevator door and the fire-protection-rated glazing were reviewed and the base data for improving way about the fire performance criteria were suggested.

충돌하중을 받는 U-채널 교량 측보의 구조적 안정성에 관한 연구

최동호,나호성,이광원,Choi,Dong-Ho,Na,Ho-Sung,Lee,Kwang-Won 한국방재학회 2008 한국방재학회 학술발표대회논문집 Vol.2008 No.1

U-Channel Bridge is effective bridge type, because its edge beam performs role of barrier and enables to reduce additional dead loads. Nevertheless, there is possibility of bridge collapse under impact load due to car crash. Also, edge beam must have ability to induce safe driving and prevent falling accidents. Therefore, this study carries out analysis of behavior of edge beam and slab and evaluation of structural stability under impact loads, based on Korean Highway Bridge Design Specifications and AASHTO LRFD Bridge Design Specification. According to analysis result, the maximum stress of edge beam and slab satisfies specification of allowable stress.