• Title/Summary/Keyword: hinge

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3-Dimensional Inelastic Behavior of Standard School Building with Various Hysteresis Models (표준학교건물의 3차원 비탄성거동에 대한 이력모델의 영향)

  • Yoon, Tae Ho
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.16 no.4
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    • pp.2917-2923
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    • 2015
  • The three dimensional inelastic response characteristics of the standard school buildings depending on hysteresis models are reviewed. Three artificial earthquake records in accordance with KBC(Korea Building Code) are used and the inelastic response characteristics such as story shear force, story drift ratio, story displacement, hinge distribution state are reviewed with four hysteresis models. As results, story shear force is increased by maximum 27% and story drift ratio is increased by maximum 30% according to hysteresis models. Modified Takeda Model shows maximum story shear and story drift raio in longitudinal and short direction, expecting higher safety. Story shear shows minimum value with Clough Model in both directions and story drift ratio shows minimum with Takeda model in longitudinal and with Clough model in short direction, so these models are expected to decrease the safety ratio.

Seismic Performance of Square RC Column Confined with Spirals (나선철근으로 횡구속된 정사각형 RC 기둥의 내진성능)

  • Ko, Seong Hyun
    • Journal of the Korea institute for structural maintenance and inspection
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    • v.16 no.5
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    • pp.88-97
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    • 2012
  • The objective of this research is to investigate the seismic performance and flexure-shear behavior of square reinforced concrete bridge piers with solid and hollow cross section. Test specimens were nonseismically designed with the aspect ratio 4.5 Two reinforced concrete columns were tested under constant axial load while subjected to lateral load reversals with increasing drift levels. Longitudinal steel ratio was 2.217 percent. The transverse reinforcement ratio As/($s{\cdot}h$), corresponding to 58 percent of the minimum lateral reinforcement required by Korean Bridge Design Specifications for seismic detailing, which represent existing columns not designed by the current seismic design specifications or designed by limited ductility concept. This study are to provide quantitative reference data for the limited ductility design concept and tendency for performance or damage assessment based on the performance levels such as cracking, yielding, collapse, etc. Failure behavior, ultimate displacement/drift ratio, displacement ductility, response modification factor, equivalent viscous damping ratio, residual deformation, effective stiffness, plastic hinge length, strain of reinforcements and nonlinear analysis are investigated and discussed in this paper.

Analysis of the Type of 3D Printing Development Linked with the Textile Structure Principle (텍스타일 스트럭처 원리와 연계된 3D 프린팅 개발 유형 분석)

  • Kim, Hyojin;Kim, Seongdal
    • Journal of Fashion Business
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    • v.22 no.2
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    • pp.1-13
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    • 2018
  • 3D printing technology, which is expected to play a leading role within the Fourth Industrial Revolution, is becoming distinguished not only in the space, automotive, medical and engineering industries, but also in the area of design. The fashion and textile structures created by 3D printing technology were classified into three types - basic structure, unified structure, and a new physical structure. When traditional weaving, knitting, and stitching was reinterpreted through 3D printing, there were apparent limitations in reproducing the characteristics of fabric structures due to differences in the materials and structures of traditional textiles. New physical structures are being developed to break away from merely reproducing traditional textile structures, and to bring out the characteristics of 3D printing technology. As examples of new physical structures, there are the kinematics structure which utilizes the hinge method, mesostructure cellular material, and the N12 disk structure. Such techniques potentially open a new paradigm of fashion and textile structures. Some innovative aspects of 3D printing technology may result in changes in the methods of collaboration, manufacturing, and distribution. Designers are receiving help from specialists of various backgrounds to merge 3D printing technology to create original works. Also, 3D printing not only makes personalized custom designs available, but shortens the distribution channels, foretelling a change within the fashion and textile industry.

Application of Temperature Gradient Gel Electrophoresis To cAMP Receptor Protein (온도 기울기 전기영동장치의 CAMP 수용성 단백질에 응용)

  • Gang, Jong-Back;Cho, Hyun-Young
    • Journal of Life Science
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    • v.14 no.2
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    • pp.309-314
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    • 2004
  • Cyclic AMP receptor protein (CRP) is involved in the transcriptional regulation of more than 100 genes in E. coli. CRP dimer is converted into active form via the sequential conformation change of cAMP binding pocket, hinge region and HTH DNA binding motif by binding of cAMP. The temperature gradient gel electrophoresis (TGGE) was applied to CRP protein to know whether it was an efficient technique to study the conformational transitions and the thermal stability. TGGE showed the unfolding process of wild-type and S83G CRP proteins with the temperature gradient set from 29 to 71$^{\circ}C$ on nondenaturing polyacrylamide gel. Melting temperature (Tm) was 57$\pm$1 and 55$\pm$1$^{\circ}C$ for wild-type and S83G CRP, respectively in acidic buffer[89.8 mM Glycine and 24 mM Boric acid (pH 5.8)].

Failure Behavior of Octagonal Flared RC Columns Using Oblong Hoops (장방형 띠철근을 이용한 팔각형 플레어 RC 기둥의 파괴거동)

  • Ko, Seong-Hyun
    • Journal of the Korea institute for structural maintenance and inspection
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    • v.18 no.3
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    • pp.58-68
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    • 2014
  • Transverse steel bars are used in the plastic hinge zone of columns to insure adequate confinement, prevention of longitudinal bar buckling and ductile behavior. Fabrication and placement of rectangular hoops and cross-ties in columns are difficult to construct and require larger amount of transverse steels. In this paper, to solve these problems, the new lateral confinement method using oblong hoop is proposed for the transverse confinement of columns of the oblong cross-section and flared column. The experimental study for octagonal oblong cross-section was carried out by the flared columns test in strong axis. The lateral confinement method using proposed oblong hoop detail showed satisfactory performance of lateral confinement. Therefore it can be the alternative for oblong cross-section and flared column with improved workability and cost-efficiency.

Design and calibration of a semi-active control logic to mitigate structural vibrations in wind turbines

  • Caterino, Nicola;Georgakis, Christos T.;Spizzuoco, Mariacristina;Occhiuzzi, Antonio
    • Smart Structures and Systems
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    • v.18 no.1
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    • pp.75-92
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    • 2016
  • The design of a semi-active (SA) control system addressed to mitigate wind induced structural demand to high wind turbine towers is discussed herein. Actually, the remarkable growth in height of wind turbines in the last decades, for a higher production of electricity, makes this issue pressing than ever. The main objective is limiting bending moment demand by relaxing the base restraint, without increasing the top displacement, so reducing the incidence of harmful "p-delta" effects. A variable restraint at the base, able to modify in real time its mechanical properties according to the instantaneous response of the tower, is proposed. It is made of a smooth hinge with additional elastic stiffness and variable damping respectively given by springs and SA magnetorheological (MR) dampers installed in parallel. The idea has been physically realized at the Denmark Technical University where a 1/20 scale model of a real, one hundred meters tall wind turbine has been assumed as case study for shaking table tests. A special control algorithm has been purposely designed to drive MR dampers. Starting from the results of preliminary laboratory tests, a finite element model of such structure has been calibrated so as to develop several numerical simulations addressed to calibrate the controller, i.e., to achieve as much as possible different, even conflicting, structural goals. The results are definitely encouraging, since the best configuration of the controller leaded to about 80% of reduction of base stress, as well as to about 30% of reduction of top displacement in respect to the fixed base case.

Study on the Manufacturing of Horizontal plate armour Excavated from Mangi-Sanseong(Castle) with X-ray Radiograph (방사선투과시험에 의한 망이산성 횡장판갑(橫長板甲)의 제작기법 연구)

  • Kim, Hyunjoung;Kim, Midori;Oh, Kwangseob;Lee, Yangsu;Cho, Namchul
    • Conservation Science in Museum
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    • v.7
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    • pp.11-24
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    • 2006
  • Plate armour is an important cultural property that reflects the ancient weaponry and the manufacturing technology of ironware as they are. Among the kinds of iron armour, horizontal plate armour has been very rarely excavated, and there are a few artifacts in their unimpaired shape like the plate armour excavated from Mangisanseong. This report reviews the manufacturing technology of ancient plate armour through its radiograph using appliable nondestructive irradiation and scientific conservation treatment. The seven-tiered plate armour excavated from Mangisanseong has ring hinge to open and shut the right side neck guard. The readout result of radiograph proved iron safety guard of Godaepan (a plate that links neck plate and horizontal plate) and leather safety guard of the right armpit with plate overlap and perforation interval; perforations that seem to have linked shoulder strap on wearing the armour are also observed. In particular, it is identified that the perforation and riveting technique avoided the connection of more than three plates with a rivet. This is an important material to illustrate the best use of function of plate armour overcoming its limit.

Seismic Performance of Octagonal Flared RC Columns using Oblong Hoops (장방형 띠철근을 이용한 팔각형 플레어 RC 기둥의 내진성능)

  • Ko, Seong-Hyun
    • Journal of the Korea institute for structural maintenance and inspection
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    • v.19 no.6
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    • pp.1-9
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    • 2015
  • Transverse steel bars are used in the plastic hinge zone of columns to insure adequate confinement, prevention of longitudinal bar buckling and ductile behavior. Fabrication and placement of rectangular hoops and cross-ties in columns are difficult to construct. Details of reinforcement for rectangular section require a lot of rectangular hoops and cross-ties. In this paper, to solve these problems, the new lateral confinement method using oblong hoop is proposed for the transverse confinement of the flared column. It can be the alternative for oblong cross-section and flared column with improved workability and cost-efficiency. The final objectives of this study are to suggest appropriate oblong hoop details and to provide quantitative reference data and tendency for seismic performance or damage assessment based on the drift levels such as residual deformation, elastic strain energy. This paper describes factors of seismic performance such as ultimate displacement/drift ratio, displacement ductility, response modification factor, equivalent viscous damping ratio and effective stiffness.

Displacement Ductility of Circular RC Column According to the Spacing of Spirals (나선철근 간격에 따른 원형 RC 기둥의 변위연성도)

  • Ko, Seong Hyun
    • Journal of the Korea institute for structural maintenance and inspection
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    • v.17 no.2
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    • pp.71-82
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    • 2013
  • Eight small scale circular reinforced concrete columns (4.5 aspect ratio) were tested under cyclic lateral load with constant axial load. The selected test variables are longitudinal steel ratio (2.017%, 3.161%), transverse steel ratio, and axial load ratio (0, 0.07, 0.15). Volumetric ratio of spirals of all the columns is 0.335~0.894% in the plastic hinge region. It corresponds to 39.7~122.3% of the minimum requirement of confining steel by Korean Bridge Design Specifications, which represent existing columns not designed by the current seismic design specifications or designed by seismic concept. The final objectives of this study are to provide quantitative reference data and tendency for performance or damage assessment based on the performance levels such as cracking, yielding, steel fracture, etc. In this paper, describes mainly failure behavior, strength degradation behaviour, displacement ductility of circular reinforced concrete bridge columns with respect to test variables.

Energy Demand in Steel Structures with Buckling Restrained Braces (좌굴이 방지된 가새가 설치된 철골조 건물의 에너지 요구량)

  • 최현훈;김진구
    • Journal of the Earthquake Engineering Society of Korea
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    • v.7 no.2
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    • pp.29-37
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    • 2003
  • In this study, a story-wise distribution of hysteretic energy in steel moment resisting framse(MRF), buckling restrained braced frames(BRBF), and hinge-connected framed structures with buckling restrained braces(HBRBF) subjected to various earthquake ground excitations was investigated. Sixty earthquake ground motions recorded in different soil conditions were used to compute the energy demand in model structure. According to analysis results, the hysteretic energy in MRF and BRBF turned out to be the maximum at the base and monotonically diminishes with increasing height. However the story-wise distribution of hysteretic energy in HBRBF was relatively uniform over the height of the structure. In this case damage is not concentrated in a single story, and therefore it is considered to be more desirable than other systems. The story-wise energy distribution pattern under three different soil types turned out to be approximately the same.