• Title/Summary/Keyword: 좌굴계수

Search Result 149, Processing Time 0.029 seconds

Compressive Behavior of Steel Plate-Concrete Structures using Eco-Oriented Cement Concrete (친환경시멘트 콘크리트를 사용한 강판콘크리트구조의 압축거동)

  • Kang, Cheol-Kyu;Choi, Byong-Jeong;Jeoung, Beak-Seon
    • Journal of Korean Society of Steel Construction
    • /
    • v.24 no.5
    • /
    • pp.583-593
    • /
    • 2012
  • The domestic research of the steel plate concrete structures have been focused on the nuclear structures requiring much strong resistance. There are many advantages in the steel plate-concrete structures such as the possibility of prefabricated production and modular construction. This research tried to establish some basic design information of SC structures toward mid to low-rise general buildings with low strength. To reduce the strength mentioned, the some of the cement in weight was replaced by the soils which are traditional and environmental oriented material where the new system can be used to general buildings. This paper studied on the compressive characteristics, effective length factors, buckling loading, steel plate buckling, and stud strength using the compression member subjected to the concentrated compression loadings.

A Theoretical and Experimental Study on Forming Limits in the Flanging Processes (플랜징 공정 의 성형한계 에 대한 이론 및 실험적 연구)

  • 양동열;박승교
    • Transactions of the Korean Society of Mechanical Engineers
    • /
    • v.9 no.6
    • /
    • pp.777-787
    • /
    • 1985
  • The study is concerned with the analysis of flanging as a sheet metal working process. In terms of mechanics, the flanging process can be divided into two groups, i.e, shrink flanging and stretch flanging. In this study, the shrink flanging process is analyzed by using the proposed energy criterion and the forming limit is found for the process. The forming limit for stretch flanging is also found by employing the neckind theory. Experiments are carried out for both processes. Approximate forming limits are obtained from the experiments. An approximate method to calculate the punch force is proposed and the computed results are compared with the experimental results. It is shown that there are good agreements in forming limits and punch forces between theory and experiments.

A program development for the instability analysis of aircraft skin- stringer panel (항공기 스킨-스트링거 패널 구조물에 대한 불안정성 해석 프로그램 개발)

  • Park, Chan-Woo;Kim, Hyoun-Rea;Won, Tae-Hoon
    • Journal of the Korean Society for Aeronautical & Space Sciences
    • /
    • v.33 no.12
    • /
    • pp.92-100
    • /
    • 2005
  • An aircraft wing or fuselage panel of skin-stringer assembly can fail in a variety of instable modes under compression loads. Instability modes can be buckling of the panel, local buckling of the stringer, flexure, torsion, wrinkle and combined flexural/torsional buckling of the panel assembly. Although researches on these buckling behaviors have been carried out for a long time, there are some difficulties to apply to the practice because of complex theoretical and empirical equations. Accordingly, It is well known that leading aerospace companies are using their own in-house programs for the convenience of practical usage, but our domestic situation is that no such program has been ever developed. In this study a comprehensive program has been developed, which can identify the instability modes and the magnitude of reserve factor of the modes for the skin/stringer panel assembly under compression load. The developed program is based on the theory manual of the Airbus program APA114. For the verification, calculation of the instable reserve factors for the A320 wing panel and A380 low wing panel sections were carried out and compared with results by APA114.

Seismic Improvement of Staggered Truss Systems using Buckling Restrained Braces (비좌굴 가새를 이용한 스태거드 트러스 시스템의 내진성능향상)

  • Kim, Jin-Koo;Lee, Joon-Ho
    • Journal of the Earthquake Engineering Society of Korea
    • /
    • v.10 no.2 s.48
    • /
    • pp.11-19
    • /
    • 2006
  • In this paper the seismic performances of 4, 10, and 30-story staggered truss systems (STS) were evaluated by observing the force-displacement relationship up io failure. The results were compared with the seismic performance of conventional moment resisting frames and braced frames. According to the analysis results, the STS showed relatively satisfactory lateral load resisting capability. However, in the mid- to high-rise STS, plastic hinges formed first at the chords were transferred to vertical members of the vierendeel panels, which formed a week link and subsequently leaded to brittle collapse of the structure. Therefore to enhance the ductility of STS it would be necessary to reinforce the vertical bracing members of the virendeel panels so that the plastic hinges, once toned in cord members of a virendeel panel, spread out to virendeel panels of neighboring stories.

Energy Dissipation Demand of Braces Using Non-linear Dynamic Analyses of X-Braced Frame (비선형 동적 해석을 통한 X형 가새골조 내 가새 부재의 에너지 소산)

  • Lee, Kangmin
    • Journal of Korean Society of Steel Construction
    • /
    • v.15 no.4 s.65
    • /
    • pp.379-388
    • /
    • 2003
  • The response of single story buildings and other case studies were investigated to observe trends and develop a better understanding of the impact of some design parameters on the seismic response of Concentrically Braced Frames (CBF). While many parameters are known to influence the behavior of braced frames, the focus of this study was mostly on quantifying energy dissipation in compression and its effectiveness on seismic performance. Based on dynamic analyses of single story braced frame and case studies, a bracing member designed with bigger R and larger KL/r was found to result in lower normalized cumulative energy ratio in both cases.

Effect of Cross Beams on Live Load Distribution in Rolled H-beam Bridges (압연형강(H형강) 거더교의 가로보가 활하중 횡분배에 미치는 영향)

  • Yoon, Dong Yong;Eun, Sung Woon
    • Journal of Korean Society of Steel Construction
    • /
    • v.18 no.5
    • /
    • pp.535-542
    • /
    • 2006
  • In this study, the effects of cross beams on the lateral distribution of live loads in composite rolled H-beam girder bridges, were investigated through three-dimensional finite element analysis. The parameters considered in this study were the inertial moment ratio between the main girder and the cross beam, the presence of the cross beam, and the number of cross beams. The live load lateral distribution factors were investigated through finite element analysis and the customary grid method. The results show that there was no difference between the bridge models with and without a cross beam. The cross beam of the beam and frame types also showed almost the same live load lateral distribution factors. However, the finite element analysis showed that the concrete slab deck plays a major role in the lateral distribution of a live load, and consequently, the effect of the cross beam is not so insignificant that it can be neglected.

An Experimental Study on Stength of Slender Square Tube Columns Filled with High Strength Concrete (고강도콘크리트충전 각형강관장주의 내력에 관한 실험적 연구)

  • Seo, Seong Yeon;Chung, Jin An
    • Journal of Korean Society of Steel Construction
    • /
    • v.14 no.4
    • /
    • pp.471-479
    • /
    • 2002
  • In this paper, 18 square CFT columns filled with high-strength concrete were tested under concentric or eccentric axial loading. Two parameters of the experimental program included the buckling length-section depth ratio ($L_K$/D) and the eccentricity of the appled compressive load (e). In additon, mechanical properties such as the compressive concrete strength and compressive and tensile steel strength were measured and incorporated into the material models for the stress-strain relationships of concrete and steel. This model was used in an elasto-plastic analysis in order to predict the behavior of the slender CFT columns. Observtions of the failure mode during the tests under axial loadig were also presented. The strengths obtained from the analysis. Recommendations for Design, and Constructions of CFT structures were presented, as verified by the experimental results.

Residual Stress Measurement of Flat Welded Specimen by Electronic Speckle Pattern Interferometry (전자처리스페클패턴 간섭법을 이용한 평판 용접시험편의 잔류응력 측정)

  • Chang, Ho-Seob;Kim, Dong-Soo;Jung, Hyun-Chul;Kim, Kyung-Suk
    • Journal of the Korean Society for Nondestructive Testing
    • /
    • v.32 no.2
    • /
    • pp.149-154
    • /
    • 2012
  • The size and distribution of welding residual stress and welding deformation in welding structures have an effect on various sorts of damage like brittle failure, fatigue failure and stress corrosion cracking. So, research for this problem is necessary continuously. In this study, non-destructive technique using laser electronic speckle pattern interferometry, plate of welding specimen according to the external load on the entire behavior of residual stress are presented measurement techniques. Once, welding specimen force tensile loading, using electronic speckle pattern interferometry is measured. welding specimen of base metal and weld zone measure strain from measured result, this using measure elastic modulus. In this study, electronic speckle pattern interferometry use weld zone and base metal parts of the strain differences using were presented in residual stress calculated value, This residual stress value were calculated by numerical calculation. Consequently, weld zone of modulus high approximately 3.7 fold beside base metal and this measured approximately 8.46 MPa.

Free Vibration Analysis of Thick Plate Subjected to In-plane Force on Inhomogeneous Pasternak Foundation (비균질 Pasternak지반 위에 놓인 면내력을 받는 후판의 진동해석)

  • Lee, Yong Soo;Kim, Il Jung;Oh, Soog Kyoung
    • Journal of Korean Society of Steel Construction
    • /
    • v.15 no.3
    • /
    • pp.291-298
    • /
    • 2003
  • Recently, as the size of buildings structure becomes large increases, their mat area of building structure is supported or by an inhomogeneous foundation. This paper presents a vibration analysis on thick plates subjected to in-plane force is presented in this paper. The rectangular plate is isotropic, homogeneous, and composed of a linearly elastic material. A vibration analysis of the rectangular thick plate iwas done by useing ofarectangular finite element with 8 nodes and 9 nodes. In this study, the foundation was idealized as a Pasternak foundation model. A Pasternak foundation haves a shear layer on Winkler's model, which idealizes the foundation as a vertical spring. In order tTo analysze the vibration of a plate supported on by an inhomogeneous Pasternak foundation, the value of the Winkler foundation parameter of the central and border zones of the plate awere chosen as WFP1 and WFP2. (fFigure 4.). The Winkler foundation parameter of WFP1 and WFP2 is varied from 0 to 10, $10^2$, and $10^3$ and the shear foundation parameters is were 0, 5, and 10. The ratio of the in-plane force to the critical load iwas applied as 0.4 to 0.8

A Study on the Strength and Stiffness of Multi-Stage Cubic Truss Unit Structures (복합 입체형 정육면체 트러스 단위구조체의 강도 및 강성에 대한 해석 연구)

  • Choi, Jeongho
    • Journal of the Korea Convergence Society
    • /
    • v.10 no.4
    • /
    • pp.139-145
    • /
    • 2019
  • This paper investigated the strength and stiffness of composite truss unit structures. The model used is a core-filled model combining the Kagome model and the cube truss model. The material properties used for the analysis are 304 stainless steel with elastic modulus of 193 GPa and yield stress of 215 MPa. The theoretical equation is derived from the relative elasticity relation of Gibson - Ashby ratio, the analysis was performed using Deform 3D, a commercial tool. In conclusion, the relative elasticity for this unit model correlates with 1.25 times the relative density and constant coefficient, elasticity is inversely proportional to pore size. The relative compressive strength has a correlation with relative density of 1.25 times. Proof of this is a real experiment, the derived theoretical relationship should further consider mechanical behavior such as bending and buckling. In the future, it is hoped that the research on the elasticity and the stress according to the structure of the three-dimensional space will be continued.