• Title/Summary/Keyword: wall-supported elements

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Evaluation of rigid-end offset effect on seismic behavior of a structure subjected to Van earthquake

  • Bekiroglu, Serkan;Sahina, Abdurrahman;Sevima, Baris;Ayvaz, Yusuf
    • Structural Engineering and Mechanics
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    • v.47 no.6
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    • pp.857-879
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    • 2013
  • Numerical damage assessment of Van train station building consisting of three RC blocks due to 2011 Van Earthquakes by nonlinear dynamic analysis is presented. The structural model is created with rigid-end offsets and plastic hinges for nonlinear analysis. Rigid-end offsets are considered for connection areas and proposed for wall-supported elements. In wall-supported elements, walls take place in a limited part of the columns. Nonlinear dynamic analysis of the building with and without rigid-end offsets is performed by using real earthquake records and results are compared. The results show that rigid-end offsets have significant effects on the seismic behavior of the structures.

Local buckling behaviour of steel plate elements supported by a plastic foam material

  • Mahendran, M.;Jeevaharan, M.
    • Structural Engineering and Mechanics
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    • v.7 no.5
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    • pp.433-445
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    • 1999
  • Sandwich panels comprising steel facings and a polystyrene foam core are increasingly used as roof and wall claddings in buildings in Australia. When they are subjected to loads causing bending and/or axial compression, the steel plate elements of their profiled facing are susceptible to local buckling. However, when compared to panels with no foam core, they demonstrate significantly improved local buckling behaviour because they are supported by foam. In order to quantify such improvements and to validate the use of available design buckling stress formulae, an investigation using finite element analyses and laboratory experiments was carried out on steel plates that are commonly used in Australia of varying yield stress and thickness supported by a polystyrene foam core. This paper presents the details of this investigation, the buckling results and their comparison with available design buckling formulae.

Analytical study of buckling profile web stability

  • Taleb, Chems eddine;Ammari, Fatiha;Adman, Redouane
    • Structural Engineering and Mechanics
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    • v.53 no.1
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    • pp.147-158
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    • 2015
  • Elements used in steel structures may be considered as an assembly of number of thin flat walls. Local buckling of these members can limit the buckling capacity of axial load resistance or flexural strength. We can avoid a premature failure, caused by effects of local buckling, by limiting the value of the wall slenderness which depend on its critical buckling stress. According to Eurocode 3, the buckling stress is calculated for an internal wall assuming that the latter is a simply supported plate on its contour. This assumption considers, without further requirement, that the two orthogonal walls to this wall are sufficiently rigid to constitute fixed supports to it. In this paper, we focus on webs of steel profiles that are internal walls delimited by flanges profiles. The objective is to determine, for a given web, flanges dimensions from which the latter can be considered as simple support for this web.

Experiment and Rigid Element Analysis of R.C. Spherical Dome (철근콘크리트 구형돔의 실험 밀 강체요소해석)

  • 박강근
    • Proceedings of the Computational Structural Engineering Institute Conference
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    • 1999.04a
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    • pp.295-302
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    • 1999
  • This paper is the experimental and analytic of reinforced concrete hemisphere dome under vertical load. It is described that when the reinforced concrete hemispherical dome supported on cylindrical wall is loaded vertically, how the opening part of dome will behave mechanically The experimental and analytic model is a Hemispherical dome with opening and the meridian angle of opening is 76$^{\circ}$at the center of sphere under concentrated load around the opening, but this is reinforced by a ring is sufficient stiffness. The diagrams of crack development are represented to understand the behavior of the reinforced concrete hemispherical dome. The method of crack analysis will be applied the rigid element spring model. The rigid element spring model is a new discrete element analysis, each divided element is assumed by rigid elements without deformation which is interconnected with elasto-plastic spring system.

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Genomic Insights into Paucibacter aquatile DH15, a Cyanobactericidal Bacterium, and Comparative Genomics of the Genus Paucibacter

  • Ve Van Le;So-Ra Ko;Hee-Mock Oh;Chi-Yong Ahn
    • Journal of Microbiology and Biotechnology
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    • v.33 no.12
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    • pp.1615-1624
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    • 2023
  • Microcystis blooms threaten ecosystem function and cause substantial economic losses. Microorganismbased methods, mainly using cyanobactericidal bacteria, are considered one of the most ecologically sound methods to control Microcystis blooms. This study focused on gaining genomic insights into Paucibacter aquatile DH15 that exhibited excellent cyanobactericidal effects against Microcystis. Additionally, a pan-genome analysis of the genus Paucibacter was conducted to enhance our understanding of the ecophysiological significance of this genus. Based on phylogenomic analyses, strain DH15 was classified as a member of the species Paucibacter aquatile. The genome analysis supported that strain DH15 can effectively destroy Microcystis, possibly due to the specific genes involved in the flagellar synthesis, cell wall degradation, and the production of cyanobactericidal compounds. The pan-genome analysis revealed the diversity and adaptability of the genus Paucibacter, highlighting its potential to absorb external genetic elements. Paucibacter species were anticipated to play a vital role in the ecosystem by potentially providing essential nutrients, such as vitamins B7, B12, and heme, to auxotrophic microbial groups. Overall, our findings contribute to understanding the molecular mechanisms underlying the action of cyanobactericidal bacteria against Microcystis and shed light on the ecological significance of the genus Paucibacter.

Automated Life-Cycle Management System Based on SCM for Super High-rise Buildings Construction (SCM기반 Automated Life-Cycle Management System 구축방안 - 초고층 빌딩 커튼월을 중심으로 -)

  • Yoon Jeong-Hwan;Kim Yea-Sang;Chin Sang-Yoon;Kim Chang-Duk;Choi Yoon-Ki;Chun Jae-Youl;Lim Hyung-Chul
    • Proceedings of the Korean Institute Of Construction Engineering and Management
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    • autumn
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    • pp.430-433
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    • 2003
  • Cost, schedule, quality are the essential parts of success of every construction project. It is especially true in high-rise building construction. Among the construction components in high-rise building construction, curtain walls are very important elements for the project success because they take large portion of cost and schedule. However, curtain wall construction process are very complicated, where many entities including designers, suppliers, contractors and even maintenance contractors are involved. Therefore, control and management of their relationships and production process are critical. It is suggested that this can be solved by the concept of Supply Chain Management which is supported by the automated information technology with Radio Frequency Identification. Such concept is defined as 'Automated Life-Cycle Management System Based On SCM' and this study suggests rode map to establish the system.

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Comparison of behavior of high-rise residential buildings with and without post-tensioned transfer plate system

  • Byeonguk Ahn;Fahimeh Yavartanoo;Jang-Keun Yoon;Su-Min Kang;Seungjun Kim;Thomas H.-K. Kang
    • Computers and Concrete
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    • v.31 no.4
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    • pp.337-348
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    • 2023
  • Shear wall is commonly used as a lateral force resisting system of concrete mid-rise and high-rise buildings, but it brings challenges in providing relatively large space throughout the building height. For this reason, the structure system where the upper structure with bearing, non-bearing and/or shear walls that sits on top of a transfer plate system supported by widely spaced columns at the lower stories is preferred in some regions, particularly in low to moderate seismic regions in Asia. A thick reinforced concrete (RC) plate has often been used as a transfer system, along with RC transfer girders; however, the RC plate becomes very thick for tall buildings. Applying the post-tensioning (PT) technique to RC plates can effectively reduce the thickness and reinforcement as an economical design method. Currently, a simplified model is used for numerical modeling of PT transfer plate, which does not consider the interaction of the plate and the upper structure. To observe the actual behavior of PT transfer plate under seismic loads, it is necessary to model whole parts of the structure and tendons to precisely include the interaction and the secondary effect of PT tendons in the results. This research evaluated the seismic behavior of shear wall-type residential buildings with PT transfer plates for the condition that PT tendons are included or excluded in the modeling. Three-dimensional finite element models were developed, which includes prestressing tendon elements, and response spectrum analyses were carried out to evaluate seismic forces. Two buildings with flat-shape and L-shape plans were considered, and design forces of shear walls and transfer columns for a system with and without PT tendons were compared. The results showed that, in some cases, excluding PT tendons from the model leads to an unrealistic estimation of the demands for shear walls sit on transfer plate and transfer columns due to excluding the secondary effect of PT tendons. Based on the results, generally, the secondary effect reduces shear force demand and axial-flexural demands of transfer columns but increases the shear force demand of shear walls. The results of this study suggested that, in addition to the effect of PT on the resistance of transfer plate, it is necessary to include PT tendons in the modeling to consider its effect on force demand.

Space Development and Law in Asia (아시아의 우주개발과 우주법)

  • Cho, Hong-Je
    • The Korean Journal of Air & Space Law and Policy
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    • v.28 no.2
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    • pp.349-384
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    • 2013
  • The Sputnik 1 launching in 1957 made the world recognize the necessity of international regulations on space development and activities in outer space. The United Nations established COPUOS the very next year, and adopted the mandate to examine legal issues concerning the peaceful uses of outer space. At the time, the military sector of the U.S.A. and the Soviet Union were in charge of the space development and they were not welcomed to discuss the prohibition of the military uses of outer space at the legal section in the COPUOS. Although both countries had common interests in securing the freedom of military uses in outer space. As the social and economic benefits derived from space activities have become more apparent, civil expenditures on space activities have continued to increase in several countries. Virtually all new spacefaring states explicitly place a priority on space-based applications to support social and economic development. Such space applications as satellite navigation and Earth imaging are core elements of almost every existing civil space program. Likewise, Moon exploration continues to be a priority for such established spacefaring states as China, Russia, India, and Japan. Recently, Companies that manufacture satellites and ground equipment have also seen significant growth. On 25 February 2012 China successfully launched the eleventh satellite for its indigenous global navigation and positioning satellite system, Beidou. Civil space activities began to grow in China when they were allocated to the China Great Wall Industry Corporation in 1986. China Aerospace Corporation was established in 1993, followed by the development of the China National Space Administration. In Japan civil space was initially coordinated by the National Space Activities Council formed in 1960. Most of the work was performed by the Institute of Space and Aeronautical Science of the University of Tokyo, the National Aerospace Laboratory, and, most importantly, the National Space Development Agency. In 2003 all this work was assumed by the Japanese Aerospace Exploration Agency(JAXA). Japan eases restrictions on military space development. On 20 June 2012 Japan passed the Partial Revision of the Cabinet Establishment Act, which restructured the authority to regulate Japanese space policy and budget, including the governance of the JAXA. Under this legislation, the Space Activities Commission of the Ministry of Education, Culture, Sports, Science, and Technology, which was responsible for the development of Japanese space program, will be abolished. Regulation of space policy and budget will be handed over to the Space Strategy Headquarter formed under the Prime Minister's Cabinet. Space Strategy will be supported by a Consultative Policy Commission as an academics and independent observers. By revoking Article 4 (Objectives of the Agency) of a law that previously governed JAXA and mandated the development of space programs for "peaceful purposes only," the new legislation demonstrates consistency with Article 2 of the 2008 Basic Space Law. In conformity with the principles laid down in the 1967 Outer Space Treaty JAXA is now free to pursue the non-aggressive military use of space. New legislation is the culmination of a decade-long process that sought ways to "leverage Japan's space development programs and technologies for security purposes, to bolster the nation's defenses in the face of increased tensions in East Asia." In this connection it would also be very important and necessary to create an Asian Space Agency(ASA) for strengthening cooperation within the Asian space community towards joint undertakings.

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Historical Studies on the Nameless Buildings at the Jondeokjeong Area in Donggwoldo (동궐도상의 존덕정 영역에 나타난 무편액 건물의 조영사적 고찰)

  • Jung, Woo Jin;Sim, Woo Kyung
    • Korean Journal of Heritage: History & Science
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    • v.45 no.1
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    • pp.148-173
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    • 2012
  • The rear garden in Donggwol Palace which shared with the Changdeok Palace and the Changgyeong Palace is the salient places of technology and idea reflected the phases of the times of the Joseon Dynasty, so it is certainly one of the best Korean garden cultures. The rear garden in Donggwol which was not only the secret garden for the rest of royal family but also used as symbolic places for the various ceremonies and training its human resources has been considerably destroyed through the period of Japanese colonial rule. Thus the rear garden areas at north of Changkyung Palace were entirely transformed and a few territory from Juhabru(宙合樓) to Ongnyucheon(玉流川) keep up its surviving as the rear garden. The area of Jondeokjeong(尊德亭) which become subject on this studies from among these was constructed as flower garden after development of Ongnyucheon. The areas of Simchujeong(深秋亭), Cheoknoedang(滌惱堂), Pyemwoosa(?愚?), Mangchunjeong(望春亭), Chunhyagak(天香閣), Chungsimjeong(淸心亭) around Jondeokjeong, were situated among the beautiful scenery with the flowers and ponds. But there are only Jondeokjeong and Pyemwoosa at this moment, and the other pavilions was destroyed and transformed. For these reasons, in this studies, the formative purposes were investigated through analysing water elements, planting, ornaments and so on. According to these reasons, historical records and realities of garden construction of five pavilions : Simchujeong, Mangchunjeong, Cheoknoedang, Chunhyagak, Chungyeongak(淸燕閣) were considered to give authenticity to the restoration and reorganization as well as to accumulate basic knowledge about the conservation of environment surrounded garden architectures. These pavilions appeared at Gunggwolgi(宮闕志) and Joseonwangzosilok(朝鮮王朝實), but their names were not appeared at Donggwoldo(東闕圖). So they were ascertained through all of literatures on Donggwol Palace. Cheoknoedang and Simchujeong among these buildings could be found out as the existed buildings and the uncertain building at the northwest of Jondeokjeong was estimated as the name to Chunhyagak or Mangchunjeong. And the hypothesis that the wall surrounding Taichungmoon(太淸門) should be belong to Chungyeongak was supported. In addition, the area which did not known in connection with name and use on northeast at the Changdeok Palace, and had regarded as an impasses in the studies of Donggwoldo and the rear garden in Donggwol Palace, but the historical records of using by Yeonsangun(燕山君) and Sukjong(肅宗) were discovered at this study. And it could be uncovered that the obscure spatial space was a separate house only for king and he enjoyed play there unnoticing to others belong to palace.