• Title/Summary/Keyword: 유효세장비

Search Result 24, Processing Time 0.032 seconds

A Study on the Buckling Strength and Effective Length of Tubular Member with Gusset Plate Considering End Restraints (단부구속효과를 고려한 관통 가셋트 부착 강관부재의 좌굴내력 및 유효세장비 산정에 관한 연구)

  • Kim, Woo Bum
    • Journal of Korean Society of Steel Construction
    • /
    • v.15 no.2
    • /
    • pp.159-165
    • /
    • 2003
  • A tubular member with through-gusset plate is often used to transmit axial compression in an electric transmission towers. In current code, the strength of tubular member is evaluated with an effective length factor k=0.9 without considering the deformation of boundary element. A buckling strength of member with end gusset plate is affected by stiffness ratio($\beta$) and the length ratio(G) between main tubular member and end gusset plate. In this study theoretical mechanism based on the elastic buckling behavior was investigated, and finite element analysis was performed to propose a formula for the buckling strength and effective length factor of tubular member in elsatic and inelastic ranges.

Hysteretic Behavior of Compressive Braces upon Repeated Cyclic Loading Based on the Review of Existing Data (기존 실험 자료를 통한 압축 철골가새의 반복 이력거동에 관한 고찰)

  • Lee, Kangmin
    • Journal of Korean Society of Steel Construction
    • /
    • v.15 no.4 s.65
    • /
    • pp.359-368
    • /
    • 2003
  • Design and detailing requirements of seismic provisions for Concentrically Braced Frames (CBF) were specified based on the premise that bracing members with large KL/r and low b/t have superior seismic performance. However, relatively few tests have been done to investigate the cyclic behavior of CBF. Therefore, the question lies on whether the compression member of CBF plays as significant a role as what has been typically assumed by design providers. In this paper, existing experimental data were reviewed to quantify the extent of hysteretic energy achieved by bracing members in past compression tests as well as the extent of degradation of the compression force given repeated cycling loading.

Determination of Effective Buckling Length of Plane Frames using Elastic and Inelastic System Buckling Analysis (탄성 및 비탄성 좌굴 고유치해석을 이용한 강뼈대구조의 유효좌굴길이)

  • Song, Ju-Young;Kyung, Yong-Soo;Kim, Moon-Young
    • Journal of the Computational Structural Engineering Institute of Korea
    • /
    • v.18 no.2
    • /
    • pp.169-179
    • /
    • 2005
  • An improved method for evaluating effective buckling lengths of beam-column members in plane frames is newly proposed based on system inelastic buckling analysis. To this end, the tangent stiffness matrix of be am-column elements is first calculated using stability functions and then the inelastic buckling analysis method is presented. The scheme for determining effective length of individual members is also addressed. Design examples and numerical results ?uc presented to show the validity of the proposed method.

Dynamic problem of Beams with Geometric nonlinear analysis research by the Collocation Method (선점법에 의한 기하학적 비선형을 고려한 보의 동적문제 해석 연구)

  • Park, Sung-Jin;Son, Jee-hyun
    • Proceedings of the Korean Society of Disaster Information Conference
    • /
    • 2015.11a
    • /
    • pp.134-137
    • /
    • 2015
  • 본 연구에서는 다른 해법과 비교하여, 비선형 진동문제 선점법 적용성, 유효성을 확인하고, F.E.M 결과와의 응답 곡선에 비교하여, 비선형 동적응답문제의 선점법 적용성을 연구한다. 또한 축방향 관성은 세장비가 크기에 따라 그 영향이 어떻게 나타나는지 연구한다.

  • PDF

A Study on Stress Recovery Analysis of Dimensionally Reducible Composite Beam Structure with High Aspect Ratio using VABS (VABS를 이용한 높은 세장비를 가진 복합재료 보 구조의 차원축소 및 응력복원 해석기법에 대한 연구)

  • Ahn, Sang Ho
    • Journal of the Computational Structural Engineering Institute of Korea
    • /
    • v.29 no.5
    • /
    • pp.405-411
    • /
    • 2016
  • This paper presented the theory related to a two dimensional linear cross-sectional analysis, recovery relationship and a one-dimensional nonlinear beam analysis for composite beam with initial twist and high aspect ratio. Using VABS including related theory, preceding research data of the composite wing structure has been modeled and compared. Cross-sectional analysis was performed and 1-D beam was modeled at cutting point including all the details of real geometry and material. The 3-D strain distribution and margin of safety at recovery point was calculated based on the global behavior of the 1-D beam analysis and visualize numerical results.

Design Equation of Reinforced Concrete Walls for Opening Configurations (개구부 형상을 고려한 철근콘크리트 벽체의 설계식 제안)

  • Lee, Dong-Jun;Oh, Soon-Taek
    • Journal of the Korea institute for structural maintenance and inspection
    • /
    • v.14 no.3
    • /
    • pp.131-137
    • /
    • 2010
  • 12 trial-scale wall panels are tested and evaluated to investigate the ultimate load capacity of axially loaded concrete walls with various opening configurations. The experimental tests have been undertaken to obtain data for the modification of existing equations. A new design equation has been generated using the precise test data and it incorporates the unique length factors. This new design equation for concrete walls with openings is then compared with existing code formulae.

An analysis of horizontal deformation of a pile in soil using a continuum soil model for the prediction of the natural frequency of offshore wind turbines (해상풍력터빈의 고유진동수 예측을 위한 지반에 인입된 파일의 연속체 지반 모델 기반 수평 거동 해석)

  • Ryue, Jungsoo;Baik, Kyungmin;Lee, Jong-Hwa
    • The Journal of the Acoustical Society of Korea
    • /
    • v.35 no.6
    • /
    • pp.480-490
    • /
    • 2016
  • As wind turbines become larger and lighter, they are likely to respond sensitively by dynamic loads applied on them. Since the responses at resonances are particularly interested, it is required to be able to predict natural frequencies of wind turbines reliably at early design stage. To achieve this, the foundation-soil analysis is needed to be carried out and a finite element approach is adopted in general. However, the finite element approach would not be appropriate in early design stage because it demands heavy efforts in pile-soil modelling and computing facilities. On the contrary, theoretical approaches adopting linear approximations for soils are relatively simple and easy to handle. Therefore, they would be a useful tool in predicting a pile-soil interaction, particularly in early design stage. In this study an analysis for a pile inserted in soil is performed. The pile and soil are modelled as a beam and continuum medium, respectively, within an elastic range. In this analysis, influence factors at the pile head for lateral loads are predicted by means of this continuum approach for various length-diameter ratios of the pile. The influence factors predicted are validated with those reported in literature, proposed from a finite element analysis.

Application of a Fictitious Axial Force Factor to Determine Elastic and Inelastic Effective Lengths for Column Members of Steel Frames (강프레임 기둥 부재의 탄성 및 비탄성 유효좌굴길이 산정을 위한 가상축력계수의 적용)

  • Choi, Dong Ho;Yoo, Hoon;Lee, Yoon Seok
    • KSCE Journal of Civil and Environmental Engineering Research
    • /
    • v.30 no.2A
    • /
    • pp.81-92
    • /
    • 2010
  • In design of steel frames, it is generally believed that elastic system buckling analysis cannot predict real behaviors of structures, while inelastic system buckling analysis can give informative buckling behaviors of individual members considering inelastic material behavior. However, the use of Euler buckling equation with these system buckling analyses have the inherent problem that the methods evaluate unexpectedly large effective lengths of members having relatively small axial forces. This paper proposes a new method of obtaining elastic and inelastic effective lengths of all members in steel frames. Considering a fictitious axial force factor for each story of frames, the proposed method determines the effective lengths using the inelastic stiffness reduction factor and the iterative eigenvalue analysis. In order to verify the validity of the proposed method, the effective lengths of example frames by the proposed method were compared to those of previously established methods. As a result, the proposed method gives reasonable effective lengths of all members in steel frames. The effect of inelastic material behavior on the effective lengths of members was also discussed.

A Study on the Effective Length Factor for Steel Plate-Concrete Structures using Cementless Concrete (무시멘트 콘크리트를 활용한 강판콘크리트 구조의 유효좌굴길이 계수 분석에 관한 연구)

  • Han, Myoung-Hwan;Choi, Byong-Jeong
    • Journal of the Korea Academia-Industrial cooperation Society
    • /
    • v.19 no.5
    • /
    • pp.661-671
    • /
    • 2018
  • Domestic studies on steel plate concrete structures have focused on nuclear structures with high strength. In this study, the SC structure was applied to the general structure, and the SC structure that is advantageous in terms of safety and construction was limited to a special structure. As a basic study for applying SC, this paper proposes basic design information of a SC structure applying cement concrete to plan the structure, which is suitable for eco - friendliness by replacing concrete cement, an important factor in a SC structure, with blast furnace slag. This study examined the compression characteristics and the effective length factor under central compression load. To calculate the effective length factor, the Euler column theory was applied without applying plate theory. The effective length factor was calculated from the yield strength of the steel plate, buckling of the steel plate, and the point at which the concrete was broken. In addition, this study examined whether the maximum compressive strength meets the national and international reference equations with the slenderness ratio (B/t) as a parameter. By analyzing the buckling of the specimen by applying the column theory and selecting the strain of the measured steel plate, the effective length factor was analyzed and compared with the value presented in the reference equation.

Stability Design of Steel Frames considering Initial Imperfection based on Second-Order Elastic Analysis (2차 탄성해석을 이용한 강뼈대구조의 초기결함 좌굴설계)

  • Kyung, Yong Soo;Lee, Chang Hwan;Kim, Moon Young
    • KSCE Journal of Civil and Environmental Engineering Research
    • /
    • v.28 no.4A
    • /
    • pp.465-474
    • /
    • 2008
  • Generally design of frame structures composed of beam-column member is accomplished by stability evaluation of each member considering the effective buckling length. This study selects a member of the smallest non-dimension slenderness ratio using the buckling eigenvalue calculated by the elastic buckling eigen-value analysis and axial force of the each member, and decides the initial deflection quantity reflected geometric and material nonlinearities from a suggested equation on the base of standard strength curve of Korea Bridge Design Code. Second-order elastic analysis applying the initial deflection is executed and the stability of each member is evaluated and decides ultimate strength. Through examples of eight-stories and four-stories plane frame structures, the evaluation of the stability is compared with the existing method and ultimate strength of the suggested method is compared with ultimate strength by the nonlinear inelastic analysis. Through these procedures, the increasing of effective buckling length by elastic buckling eigenvalue analysis is prevented from a new design method that considers initial imperfections. And the validity of this method is proved.