• Title/Summary/Keyword: column design

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Exergy Analysis of Nitrogen Distillation Column in the Cryogenic Air Separation Process (심랭식공기분리공정에서 질소증류탑의 엑서지 해석)

  • 용평순;이성철
    • Progress in Superconductivity and Cryogenics
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    • v.4 no.1
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    • pp.145-150
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    • 2002
  • The distillation column is one of large energy consumable units in the cryogenic air separation process and the accurate energy analysis of this unit is necessary for choice of energy saving process. In this work, the energy method was adopted for energy analysis of a cryogenic nitrogen distillation column. In order to designing the energy saving distillation column, the exergy distribution of feed air, exergy efficiency and exergy loss for process condition was investigated and the optimal process condition to minimize the exergy loss was found. The result from this work can be used as a guideline for the choice of the process design conditions and efficiency improvement of cryogenic distillation column.

Influence of shear deformation of exterior beam-column joints on the quasi-static behavior of RC framed structures

  • Costa, Ricardo J.T.;Gomes, Fernando C.T.;Providencia, Paulo M.M.P.;Dias, Alfredo M.P.G.
    • Computers and Concrete
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    • v.12 no.4
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    • pp.393-411
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    • 2013
  • In the analysis and design of reinforced concrete frames beam-column joints are sometimes assumed as rigid. This simplifying assumption can be unsafe because it is likely to affect the distributions of internal forces and moments, reduce drift and increase the overall load-carrying capacity of the frame. This study is concerned with the relevance of shear deformation of beam-column joints, in particular of exterior ones, on the quasi-static behavior of regular reinforced concrete sway frames. The included parametric studies of a simple sub-frame model reveal that the quasi-static monotonic behavior of unbraced regular reinforced concrete frames is prone to be significantly affected by the deformation of beam-column joints.

Operating System Design of Multi Beam Control System with Miniaturized Electron Beam Columns (초소형 전자빔을 이용한 멀티 전자빔 운영 시스템 설계)

  • Lim, Sun Jong;Kim, Ho Seob
    • Laser Solutions
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    • v.18 no.4
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    • pp.12-16
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    • 2015
  • The research on multi electron beam systems is being carried out by various methods. We are studying multi electron beam system using miniaturized electron beam columns. The column consists of electrostatic lenses, electrostatic deflector and tip emitter. Our operating system controls 4 column array, captures images of each column and maintains the instrument. We present the usefulness of our operating system for multi columns by capturing images of each column.

A study on the finish work of Reinforced Con'c slab for improving workability in the column shortening compensation. (기둥축소량 보정법에 있어서 시공성 향상을 위한 RC 슬래브 표면마무리에 관한 연구)

  • 소광호;이재옥;양극영
    • Proceedings of the Korean Institute of Building Construction Conference
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    • 2003.05a
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    • pp.147-152
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    • 2003
  • Passage of time axial shortening in the cores and columns of tall concrete buildings requires special attention to ensure proper behavior for strength of the structure and the nonstructural element. The effects of column shortening, both elastic and inelastic, take on added significance and need special consideration in design and construction with increased height of structures. In this paper, the compensation method of column shortening for reinforced concrete structure are introduced. It could be concluded that the survey is a significant factor for the compensation instance of column shortening.

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Energy dissipation of steel-polymer composite beam-column connector

  • Wang, Yun-Che;Ko, Chih-Chin
    • Steel and Composite Structures
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    • v.18 no.5
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    • pp.1161-1176
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    • 2015
  • The connection between a column and a beam is of particular importance to ensure the safety of civil engineering structures, such as high-rise buildings and bridges. While the connector must bear sufficient force for load transmission, increase of its ductility, toughness and damping may greatly enhance the overall safety of the structures. In this work, a composite beam-column connector is proposed and analyzed with the finite element method, including effects of elasticity, linear viscoelasticity, plasticity, as well as geometric nonlinearity. The composite connector consists of three parts: (1) soft steel; (2) polymer; and (3) conventional steel to be connected to beam and column. It is found that even in the linear range, the energy dissipation capacity of the composite connector is largely enhanced by the polymer material. Since the soft steel exhibits low yield stress and high ductility, hence under large deformation the soft steel has the plastic deformation to give rise to unique energy dissipation. With suitable geometric design, the connector may be tuned to exhibit different strengths and energy dissipation capabilities for real-world applications.

Experimental study on lateral behavior of precast wide beam-column joints

  • Kim, Jae Hyun;Jang, Beom Soo;Choi, Seung-Ho;Lee, Yoon Jung;Jeong, Ho Seong;Kim, Kang Su
    • Earthquakes and Structures
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    • v.21 no.6
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    • pp.653-667
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    • 2021
  • In this study, cyclic loading tests were conducted on the precast concrete (PC) wide beam (WB)-column joints. Two beam-column joint specimens were fabricated with the arrangement and anchorage details of the reinforcing bars penetrating the beam and column as variables. Through a cyclic loading test, the lateral load-story drift ratio responses, seismic performance characteristics (e.g., ductility, overstrength factor), energy dissipation, strength and stiffness degradations of each specimen were compared and analyzed based on the various indices and the current structural codes (ACI 318-19 and ACI 374.1-05 report). In addition, the shear lag effect was confirmed through the gauge values of the PC beam, and the differences in seismic performance between the specimens were identified on that basis.

Simplified analysis method for anti-overturning of single-column pier girder bridge

  • Liang Cao;Hailei Zhou;Zhichao Ren
    • Structural Engineering and Mechanics
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    • v.91 no.4
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    • pp.403-416
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    • 2024
  • The single-column pier girder bridge, due to its low engineering cost, small footprint, and aesthetic appearance, is extensively employed in urban viaducts and interchange ramps. However, its structural design makes it susceptible to eccentric loads, flexural-torsional coupling effects, and centrifugal forces, among others. To evaluate its anti-overturning performance reasonably, it is crucial to determine the reaction force of the support for the single-column pier girder bridge. However, due to the interaction between vehicle and bridge and the complexity of vibration modes, it poses a significant challenge to analyze the theory or finite element method of single-column pier girder bridges. The unit load bearing reaction coefficient method is proposed in this study to facilitate the static analysis. Numerous parameter analyses have been conducted to account for the dynamic amplification effect. The results of these analyses reveal that the dynamic amplification factor is independent of road surface roughness but is influenced by factors such as the position of the support. Based on parameter analysis, the formula of the dynamic amplification factor is derived by fitting.

Analysis of Optimized Column-pile Length Ratio for Supplementing Virtual Fixed Point Design of Bent Pile Structures (단일 현장타설말뚝의 가상고정점 설계를 보완한 상부기둥-하부말뚝 최적 길이비 분석)

  • Jeong, Sangseom;Kim, Jaeyoung
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.33 no.5
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    • pp.1915-1933
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    • 2013
  • In this study, the virtual fixed point analysis and 3D fully modeling analysis for bent pile structures are conducted by considering various influencing factors and the applicability of the virtual fixed point theory is discussed. Also, the optimized column-pile length ratio is analyzed for supplementing virtual fixed point design and examining a more exact behavior of bent pile structures by taking into account the major influencing parameters such as pile length, column and pile diameter, reinforcement ratio and soil conditions. To obtain the detailed information, the settlement and lateral deflection of the virtual fixed point theory are smaller than those of 3D fully modeling analysis. On the other hand, the virtual fixed point analysis overestimates the axial force and bending moment compared with 3D fully modeling analysis. It is shown that the virtual fixed point analysis cannot adequately predict the real behavior of bent pile structures. Therefore, it is necessary that 3D fully modeling analysis is considered for the exact design of bent pile structures. In this study, the emphasis is on quantifying an improved design method (optimized column-pile length ratio) of bent pile structures developed by considering the relation between the column-pile length ratio and allowable lateral deflection criteria. It can be effectively used to perform a more economical and improved design of bent pile structures.

Prediction of Column Axial Force in X-braced Seismic Steel Frames Considering Brace Buckling (가새좌굴을 고려한 X형 내진 가새골조의 기둥축력 산정법)

  • Yoon, Won Soon;Lee, Cheol Ho;Kim, Jeong Jae
    • Journal of Korean Society of Steel Construction
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    • v.26 no.6
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    • pp.523-535
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    • 2014
  • According to the capacity design concept underlying current steel seimsic provisions, the braces in concentrically braced frames should dissipate seismic energy through cyclic tension yielding and compression buckling. On the other hand, the beams and the columns in the braced bay should remain elastic for gravity load actions and additional column axial forces resulting from the brace buckling and yielding. However, due to the difficulty in accumulating the yielding and buckling-induced column forces from different stories, empirical and often conservative approaches have been used in design practice. Recently a totally different approach was proposed by Cho, Lee, and Kim (2011) for the prediction of column axial forces in inverted V-braced frames by explicitly considering brace buckling. The idea proposed in their study is extended to X-braced seismic frames which have structural member configurations and load transfer mechanism different from those of inverted V-braced frames. Especially, a more efficient rule is proposed in combining multi-mode effects on the column axial forces by using the modal-mass based weighting factor. The four methods proposed in this study are evaluated based on extensive inelastic dynamic analysis results.

Behavior of Wide Beam-Column Interior Joint with Slab (횡력을 받는 넓은 보-기둥 내부 접합부의 거동 평가)

  • Lee, Bum-Sik;Park, Seong-Sik;Park, Ji-Young
    • Land and Housing Review
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    • v.3 no.4
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    • pp.433-449
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    • 2012
  • An experimental investigation was conducted to study the behavior of RC wide beam-column joints with slab subjected to reversed cyclic loads under constant axial load. Six half scale interior wide beam-column assemblies representing a portion of a frame subjected to simulated seismic loading were tested, including three specimens without slab and three specimens with slab. The primary variables were the ratio of column-to-beam flexural capacity ($M_r={\Sigma}M_c/{\Sigma}M_b$ ; 0.77~2.26), ratio of the column-to-beam width (b/H ; 1.54, 1.67). Test results are shown that (1) the current design code and practice for interior joints(type 2) are apply to the wide beam-high strength concrete column. (2) the presence of a slab have an effect on the performance of the wide beam-high strength concrete column interior joints(type 2). therefore in the design of the wide beam-high strength concrete column interior joints(type 2), the width of slab effective as a T beam flange should be considered. It was show that the case of the ratio of column-to-beam flexural capacity is more than 2.0, the effective width of slab are 2 times of an effective depth of wide beam, however if the ratio of column-to-beam flexural capacity is 1.4~2.0, the effective width of slab are not able to be considered.