• Title/Summary/Keyword: local buckling analysis

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Flexural Strength of HSB I-Girder Considering Inelastic Flange Local Buckling (압축플랜지 비탄성 국부좌굴을 고려한 HSB 플레이트거더의 휨강도)

  • Cho, Eun Young;Shin, Dong Ku
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.33 no.1
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    • pp.81-92
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    • 2013
  • The ultimate flexural strength of HSB I-girders, considering the effect of local bucking, was investigated through a series of nonlinear finite element analysis. The girders were selected such that the inelastic local flange buckling or the plastic yielding of compression flanges governs the flexural strength. Both homogeneous sections fabricated from HSB600 or HSB800 steel and hybrid sections with HSB800 flanges and SM570-TMC web were considered. In the FE analysis, the flanges and web were modeled using thin shell elements and initial imperfections and residual stresses were imposed on the FE model. An elasto-plastic strain hardening material was used for steels. After establishing the validity of present FE analysis by comparing FE results with test results published in the literature, the effects of initial imperfection and residual stress on the inelastic flange local buckling behavior were assessed. The ultimate flexural strengths of 60 I-girders with various compression flange slenderness were obtained by FE analysis and compared with those calculated from the KHBDC, AASHTO LRFD and Eurocode 3 provisions. Based on the comparison, the applicability of design equations in these specifications for the flexural strength of I-girder considering flange local buckling was evaluated.

A numerical method for buckling analysis of built-up columns with stay plates

  • Djafour, M.;Megnounif, A.;Kerdal, D.;Belarbi, A.
    • Structural Engineering and Mechanics
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    • v.26 no.4
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    • pp.441-457
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    • 2007
  • A new numerical model based on the spline finite strip method is presented here for the analysis of buckling of built-up columns with and without end stay plates. The channels are modelled with spline finite strips while the connecting elements are represented by a 3D beam finite element, for which the stiffness matrix is modified in order to ensure complete compatibility with the strips. This numerical model has the advantage to give all possible failure modes of built-up columns for different boundary conditions. The end stay plates are also taken into account in this method. To validate the model a comparative study was carried out. First, a general procedure was chosen and adopted. For each numerical analysis, the lowest buckling loads and modes were calculated. The basic or "pure" buckling modes were identified and their critical loads were compared with solutions obtained using analytical methods and/or other numerical methods. The results showed that the proposed numerical model can be used in practice to study the elastic buckling of built-up columns. This model is considered accurate and efficient for the local buckling of short columns and global buckling for slender columns.

Local Buckling Behaviors of Flat-Type Stiffeners in Stiffened Plate System (보강판시스템에 적용되는 판형보강재의 국부좌굴거동)

  • Kim, Kyung-Sik
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.14 no.12
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    • pp.6521-6526
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    • 2013
  • Elastic and nonlinear ultimate strength analyses were conducted to examine the effects of the stiffness and slenderness of flat-type stiffeners on ultimate in-plane strengths of a stiffened plate system. Although it is not feasible to consider local buckling in the stiffeners in elastic analysis, it was confirmed that the in-plane strengths of the stiffened plate system can be achieved by antisymmetric buckling mode when a certain level of stiffness in the stiffeners is provided. Nonlinear ultimate strength analysis, in which initial imperfection and residual stress are incorporated, showed that the ultimate strengths are sensitively affected by the mode shapes for initial imperfections. The slenderness limit for flat-type stiffeners in KHBDC (Korean Highway Bridge Design Code) was evaluated as conservative compared to the analysis results.

Design and Buckling Analysis of Earth Retaining Struts Supported by High Strength Steel Pipe and PHC Pile (고강도 강관과 PHC파일이 활용된 흙막이 버팀보의 좌굴해석 및 설계)

  • Lim, Seung Hyun;Kim, In Gyu;Kim, Sung Bo
    • Journal of Korean Society of Steel Construction
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    • v.27 no.4
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    • pp.411-422
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    • 2015
  • The design and buckling behavior of earth retaining system supported by high strength steel pipe and PHC pile under compression is presented in this study. Buckling analysis of various strut system was investigated according to the strut total length(30m, 60m, 90m), three types of built-up columns and connection condition. Buckling loads calculated by F.E analysis was compared with the theoretical solution corresponding to diagonal buckling mode, local and global buckling mode of main strut. The design of the built-up column struts are performed based on design guide for high strength steel pipes and P-M diagram for built-up column with two PHC pile section.

Case study on stability performance of asymmetric steel arch bridge with inclined arch ribs

  • Hu, Xinke;Xie, Xu;Tang, Zhanzhan;Shen, Yonggang;Wu, Pu;Song, Lianfeng
    • Steel and Composite Structures
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    • v.18 no.1
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    • pp.273-288
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    • 2015
  • As one of the most common failure types of arch bridges, stability is one of the critical aspects for the design of arch bridges. Using 3D finite element model in ABAQUS, this paper has studied the stability performance of an arch bridge with inclined arch ribs and hangers, and the analysis also took the effects of geometrical and material nonlinearity into account. The impact of local buckling and residual stress of steel plates on global stability and the applicability of fiber model in stability analysis for steel arch bridges were also investigated. The results demonstrate an excellent stability of the arch bridge because of the transverse constraint provided by transversely-inclined hangers. The distortion of cross section, local buckling and residual stress of ribs has an insignificant effect on the stability of the structure, and the accurate ultimate strength may be obtained from a fiber model analysis. This study also shows that the yielding of the arch ribs has a significant impact on the ultimate capacity of the structure, and the bearing capacity may also be approximately estimated by the initial yield strength of the arch rib.

A Study on the Evaluation Method for Bending Collapse Behavior of an Aluminum Square Tube (굽힘붕괴를 수반하는 알루미늄 사각관의 시험법에 관한 연구)

  • 이성혁;최낙삼
    • Proceedings of the Korean Society For Composite Materials Conference
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    • 2002.10a
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    • pp.123-126
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    • 2002
  • To evaluate the bending collapse behavior of an aluminum square tube, a finite element simulation for the four-point bending test was suggested. Local buckling deformation near the center of an aluminum tube specimen was induced which has been partly inserted by two steel bars. Simulation results showed good agreements with those of experiment.

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Acoustic Emmision Characteristics according to Failure Modes of Pipes with Local Wall Thinning (감육배관의 손상모드에 따른 음향방출 특성)

  • 안석환;남기우;김선진;김진환;김현수;박인덕
    • Journal of Ocean Engineering and Technology
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    • v.16 no.5
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    • pp.66-72
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    • 2002
  • Fracture behaviors of pipes with local wall thinning are very important for the integrity of nuclear power plant. However, effects of local wall thinning on strength and fracture behaviors of piping system were not well studied. Acoustic emission(AE) has been widely used in various fields because of its extreme sensitivity, dynamic detection ability and location of growing defects. In this study, we investigated failure modes of locally wall thinned pipes and AE signals by bending test. From test results, we could be divided four types of failure modes of ovalization, crack initiation after ovalization, local buckling and crack initiation after local buckling. And fracture behaviors such as elastic region, yielding region, plastic deformation region and crack progress region could be evaluated by AE counts, accumulative counts and time-frequency analysis during bending test. The result of the frequency range is expected to be basic data that can inspect plants in real-time.

A Study on Damage Process Analysis for Steel Pier Subjected to Seismic Excitation (강한 지진 하중하에서 강재 교각의 손상 거동 연구)

  • Park, Yeon Soo;Park, Keun Koo;Park, Sun Joon
    • Journal of Korean Society of Steel Construction
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    • v.12 no.3 s.46
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    • pp.251-258
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    • 2000
  • Based on the numerical investigations using steel bridge pier subjected to strong seismic excitations a new approach to seismic damage assessment for steel structures and their members has been proposed in conjunction with the suggested definition of failure state. The relevant failure form of the steel pier is evaluated. It is revealed that when a seismic load has a short period, the failure of global buckling beyond the allowable displacement is more dominant than that by that of the local buckling caused by the accumulation of plastic strain. When a seismic load is not beyond this certain part, but repeats within the range of where a plastic deformation occurs, the plastic strain is accumulated on the partial element of bottom edge of steel pier and the failure occurs by the local buckling from the accumulated plastic local strain.

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Finite element modelling of back-to-back built-up cold-formed stainless-steel lipped channels under axial compression

  • Roy, Krishanu;Lau, Hieng Ho;Lim, James B.P.
    • Steel and Composite Structures
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    • v.33 no.1
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    • pp.37-66
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    • 2019
  • In cold-formed steel structures, such as trusses, wall frames and portal frames, the use of back-to-back built-up cold-formed stainless-steel lipped channels as compression members are becoming increasingly popular. The advantages of using stainless-steel as structural members are corrosion resistance and durability, compared with carbon steel. The AISI/ASCE Standard, SEI/ASCE-8-02 and AS/NZS do not include the design of stainless-steel built-up channels and very few experimental tests or finite element analyses have been reported in the literature for such back-to back cold-formed stainless-steel channels. Current guidance by the American Iron and Steel Institute (AISI) and the Australian and New Zealand (gAS/NZS) standards for built-up carbon steel sections only describe a modified slenderness approach, to consider the spacing of the intermediate fasteners. Thus, this paper presents a numerical investigation on the behavior of back-to-back cold-formed stainless-steel built-up lipped channels. Three different grades of stainless steel i.e., duplex EN1.4462, ferritic EN1.4003 and austenitic EN1.4404 have been considered. Effect of screw spacing on the axial strength of such built-up channels was investigated. As expected, most of the short and intermediate columns failed by either local-global or local-distortional buckling interactions, whereas the long columns, failed by global buckling. All three grades of stainless-steel stub columns failed by local buckling. A comprehensive parametric study was then carried out covering a wide range of slenderness and different cross-sectional geometries to assess the performance of the current design guidelines by AISI and AS/NZS. In total, 647 finite element models were analyzed. From the results of the parametric study, it was found that the AISI & AS/NZS are conservative by around 10 to 20% for cold-formed stainless-steel built-up lipped channels failed through overall buckling, irrespective of the stainless-steel grades. However, the AISI and AS/NZS can be un-conservative by around 6% for all three grades of stainless-steel built-up channels, which failed by local buckling.

Flange Local Buckling(FLB) for Flexural Strength of Plate Girders with High Performance Steel(HSB 800) (고성능 강재(HSB 800)를 적용한 플레이트 거더의 휨강도에 대한 플랜지 국부좌굴)

  • Kim, Jeong Hun;Kim, Kyoung Yul;Lee, Jeong Hwa;Kim, Kyung Sik;Kang, Young Jong
    • Journal of Korean Society of Steel Construction
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    • v.26 no.2
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    • pp.91-103
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    • 2014
  • High performance steel for bridges(HSB 800) with a minimum tensile stress of 800MPa was recently developed. However, the study for local buckling behavior of plate girders considering interactive effects of flanges and webs is still insufficient. In this study, the flange local buckling(FLB) strength of plate girders with HSB 800 was evaluated by nonlinear finite element analysis. The flanges and webs of plate girders having I-section were modeled as 3D shell elements in the nonlinear analysis. Initial imperfection and residual stress were imposed on the plate girder. The high performance steel was modeled as a multi-linear material. Thus, parametric study of compression flanges with a compact, noncompact and slender web was performed. The flange local buckling behavior of plate girders was analyzed, and the nonlinear analysis results were compared with the nominal flexural strength of both AASHTO LRFD(2012) and KHBDC LSD(2012) codes.